Search

The limitations of oxide/oxide ceramic matrix composites lie in the need to improve their mechanical properties. It is challenging to reconcile the conflict between matrix densification at high temperature and the potential thermal damage to fibers. The concept of using element doping to control the sintering behavior of matrix was initially applied to prepare alumina-based ceramic matrix composites (CMCs). To lower the sintering temperature of the Al 2 O 3 matrix, MnO 2 dopant was used as a sintering aid. As a result, the thermal damage to alumina fibers was decreased, and the mechanical properties of the composite were significantly enhanced. The effect of MnO 2 content on the bending strength and micro-morphology of the composite was investigated. The composite exhibits optimal mechanical properties with a 0.01 wt% MnO 2 doping, and its bending strength is approximately 405 MPa. The investigation aimed to determine the mechanism by which the fluctuation in micro-mechanical properties of the composites with different MnO 2 contents. After the thermal aging at 1000℃ for 500 h, the bending strength of the N610/Al 2 O 3 -0.01 composite decreases to 297 MPa. The evolution and mechanism of thermal aging damage have been studied. [ABSTRACT FROM AUTHOR]

Fused silica ceramic has become one of the most widely used radome materials in the world since the 1970s. But its poor mechanical properties restricted its application to some extent. To improve the mechanical properties of the fused silica ceramic and keep its characteristic for radome materials, silicon nitride (Si3N4) whisker‐reinforced fused silica ceramics were prepared by a slip‐casting method in the work. The influence of Si3N4 whisker contents on the properties of the slurry was studied, indicating that the preferable pH values of the slurry were 4–6 and whisker contents were 10 wt.%. The flexural strength of as‐prepared Si3N4w/SiO2 ceramic was about 74.35 MPa, exhibiting an increase of 7.75% over that of the pure silica sample. Its dielectric constant in the range from 8 to 12 GHz and tanδ under 10 GHz were, respectively, 3.37 and.0011. It is of great interest to find that Si3N4w/SiO2 has excellent oxidization resistance and its mass maintains even at 1270°C. [ABSTRACT FROM AUTHOR]

• A new dynamic compartmental model involving two modes of transmission (public space and households) is proposed to evaluate the impact of the metropolitan-wide quarantine on the trend and transmission pattern of the COVID-19 epidemic in Hubei, China. • The quarantine reduces more than 70% of new infections in both households and the public space, as well as the deaths caused by COVID-19 pneumonia. Household transmission is the dominant route of disease spread regardless of quarantine. • The results will provide important evidence and scientific insights to other worldwide countries that are currently under quarantine. Hubei province in China has completed cycle of quarantine-resumption in 23rd Janauary and 8th April 2020, providing a unique opportunity as for now to assess its intervention impact and the pattern of SARS-COV-2 transmission during the quarantine period. In this study, we evaluate the impact of the metropolitan-wide quarantine on the trend and transmission route of the COVID-19 epidemic in Hubei, China. The intervention reduces more than 70% of new infections in both households and the public space, as well as the deaths caused by COVID-19 pneumonia. Household transmission is the dominant route of disease spread regardless of quarantine. This will provide important evidence and scientific insights to other worldwide countries that are currently under quarantine. [ABSTRACT FROM AUTHOR]

Aurivillius type Na 0.46- x Li 0.04 Bi 0.5- x (LaNd) x /2 Bi 2 Nb 2 O 9 ceramics were prepared by a conventional solid state sintering method. The evolution of crystal structure, microstructure and corresponding electrical properties were studied. A new pseudo morphotropic phase boundary between orthorhombic to pseudo-tetragonal phases was identified near x ∼ 0.06, giving rise to the enhancement of piezoelectric properties. The resonance and antiresonance impedance modulus at rising temperatures demonstrated that the ceramics with 6 mol% La 3+ /Nd 3+ doping (NLN-6) was indeed piezoelectric in nature at 700 °C. The electrochemical impedance spectra indicated that thermally excited intrinsic oxygen vacancies were responsible for both electrical conduction and dielectric relaxation processes. The NLN-6 ceramics exhibited superior electrical properties ( d 33 ∼ 20.1 pC/N, k p ∼ 6%, T C ∼ 737 °C, ρ ∼1 MΩ·cm@600 °C) and also possessed excellent stability of piezoelectric properties with rising temperature. These results suggest that La 3+ /Nd 3+ multi- rare-earth ions modified Na 0.46 Li 0.04 Bi 2.5 Nb 2 O 9 ceramics are promising candidates for ultra-high temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

High temperature piezoelectric materials have attracted much attention owing to their potential applications for structural health monitoring and nondestructive evaluation in new jet engines, steam and nuclear plants. Nonstoichiometric (Na 0.5- x Bi 0.5+ x )Bi 2 Nb 2 O 9 high temperature piezoceramics were prepared by a conventional solid-state sintering route. The microstructure, dielectric, DC resistivity and piezoelectric properties were investigated. Pure Aurivillius phase structure only existed in a narrow region (−0.02 ≤ x < 0.02). Moreover, the anisotropic grain morphologies were significantly restrained by increasing Bi contents. The oxygen vacancies were artificially tailored in nonstoichiometric compositions. The dynamic piezoelectricity as a function of the poling electric field was also studied and underlying physic mechanism was discussed. (Na 0.48 Bi 0.52 )Bi 2 Nb 2 O 9 ceramic has the large piezoelectric coefficient ( d 33 ∼20.8pC/N), high Curie-temperature ( T C ∼796 °C) and low thermal aging rate (<10% @700 °C), indicating that it is a promising candidate for ultra-high temperature piezoelectric sensor applications. [ABSTRACT FROM AUTHOR]

(Li, Ce, La) multi-doped Na 0.5 Bi 2.5 Nb 2 O 9 ceramics were prepared by a conventional solid state sintering method. Microstructure of sintered ceramics was examined by the X-ray diffraction and scanning electron microscopy. The introduction of voluminous La 3+ cations decreases the degree of lattice distortion, leading a lower Curie-temperature. The detailed electrical conduction behaviors were determined by the electrochemical impedance spectra (EIS). The electrical properties were investigated as a function of frequency (10 2 –10 6 Hz) at various temperatures (350–750 °C). The underlying physical mechanism of electrical properties at high temperature for multi-rare-earth doping NBN-based was studied via an assistance of EIS techniques. There were a set of Debye-like relaxation peaks in the imaginary part of impedance and electric modulus data. Oxygen vacancies are responsible for both ac conduction and dielectric relaxation processes. A discontinuous variation of the exponent parameter n is found owing to a ferroelectric-ferroelastic phase transition around 550 °C. [ABSTRACT FROM AUTHOR]

Pr/Mn- codoped Aurivillius type Ca 0.95 []Bi 2 Nb 2 O 9 ([] denoted as A-site vacancies) piezoelectric ceramics were prepared by a conventional solid state sintering method. The microstructure and correlated electrical properties were investigated. A set of dielectric relaxation peaks was observed in the high doping level of Pr/Mn-doped CBN ceramics. The primary and secondary processes dominate the dc conduction and dielectric relaxation processes owing to various activation energies. The localized hopping of oxygen vacancies near the Mn doping centers causes the dielectric relaxation behavior. On the other hand, the long-range continuous transformation of oxygen vacancies is responsible for the dc conduction process, which has a higher energy barrier than that of the localized hopping. The thermal depolarization behavior of piezoelectric properties was also studied. [ABSTRACT FROM AUTHOR]

• An age-structured mathematical model on mumps outbreaks in Jiangsu, China is proposed and analyzed. • Three different stages of no vaccine, effectively controlled and resurgence stages are considered. • Patterns of mumps dynamics are simulated and compared based on data in Jiangsu from January 2005 to May 2019. • The time average basic reproduction number may be lower or over estimated the real one. • Changes in seasonal transmission patterns and demographic structures may be reasons of mumpsre-emerging. Measles, mumps and rubella (MMR) vaccine program was introduced in Jiangsu province of China in May 2008 and has been greatly contributed to decreasing of mumps cases. However, mumps has been resurging since May 2015. A number of studies have put forward that the resurgence of mumps is due to vaccine failure. In this paper, we investigated the other reasons for the resurging of mumps, such as the changes in seasonal transmission patterns and demographic structures, by using an age-structured mathematical model. We divided the history (January 2005 to May 2019) of mumps epidemics of Jiangsu province into three different stages: No vaccine stage (January 2005 to December 2008), effectively controlled stage (January 2009 to December 2014) and resurgence stage (January 2015 to May 2019). The features of mumps epidemics in three stages are compared under different demographic structures with same physical contact rate. The mumps transmission rate was increased in summer and dropped in November in stage III compared with that in stage I. The changes in demographic structures give a good explanation why the mumps outbreaked among children around 10 years old in stage I and around 5 years old in stage III. We have a conclusion that the vaccine failure, changes in seasonality and demographic structures were associated with the mumps outbreaks in recent years in Jiangsu province, China. We give the patterns of mumps dynamics considering age, vaccine, seasonality and demographic structures, which can help health program planners to implement more preventive interventions in mumps control during the period of higher risk of infection. [ABSTRACT FROM AUTHOR]

Aurivillius phase Bi 3 Ti 1− x Ta x Nb 1− x W x O 12 high temperature piezoceramics were prepared by a conventional solid state reaction method. The crystal structure, dielectric, electrical conduction and piezoelectric properties were systematically studied. Pure or modified Bi 3 TiNbO 9 ceramics revealed the presence of only two-layered Aurivillius phase, indicating that Ta/W doping entered into the B-site of pseudo-perovskite structure and formed solid solutions. The Curie temperature had a strong reliance on the structural distortion. Furthermore, Ta/W dopants act as a donor doping, decrease the number of oxygen vacancies and facilitate the domain wall motion. As a result, Ta/W modifications significantly increase the DC resistivity and piezoelectric properties. Bi 3 Ti 0.98 Ta 0.02 Nb 0.98 W 0.02 O 12 ceramics possess the optimum d 33 value (∼12.5 pC/N) together with a high T C point (∼893 °C). Moreover, the resonance–antiresonance spectra demonstrate that the Ta/W-BTN ceramics are indeed piezoelectric in nature at 600 °C. The d 33 value of BTTNW-2 ceramic remains ∼12.2 pC/N after annealing at 700 °C. These factors suggest that the BTTNW-based ceramic is a promising candidate for ultra-high temperature sensor applications. [ABSTRACT FROM AUTHOR]

Aurivillius-type Bi 4 Ti 3- x W x /2 Nb x /2 O 12 ceramics were prepared by a conventional solid-state sintering method. The XRD patterns demonstrated that all compositions were a single three layered crystalline structure, involving a reduction of lattice distortion with an increase in W/Nb doping level. The electrical properties including dielectric, electrical conduction and piezoelectric properties were tailored by W/Nb additives. The Curie-temperature decreased, whereas the electrical resistivity drastically increased with introduction of W/Nb donor dopants. As a result, a high electric field can be applied during the poling process. The Bi 4 Ti 2.9 W 0.05 Nb 0.05 O 12 ceramics exhibited optimum piezoelectric coefficient ( d 33 ∼22.8 pC/N), large remnant polarization (2 P r ∼26.8 μC/cm 2 @ 200 °C) together with a high Curie temperature ( T C ∼635 °C). Furthermore, this composition possessed a wide sintering window with outstanding piezoelectric properties. These parameters indicate that Bi 4 Ti 2.9 W 0.05 Nb 0.05 O 12 -based ceramic is a promising candidate for high temperature piezoelectric applications. [ABSTRACT FROM AUTHOR]

• Lanthanide doped CBN-based ceramics were prepared. • Lattice distortion and microstructure were influenced by the dopants. • Ce-CBN ceramics exhibit some unique electrical properties. • The variation of piezoelectric and resistance refers to the oxygen vacancies induced by Ce-doping. Calcium bismuth niobate (CaBi 2 Nb 2 O 9 , CBN) is a promising candidate for high-temperature applications in aerospace, shipping, and nuclear industries, owing to its ultra-high Curie temperature (T C ∼x223C 940 °C). Lanthanide ions modified CBN based ceramics were prepared by a conventional solid-state sintering route. The crystal structure, microstructure, and high-temperature electrical properties of CBN ceramics doped by different lanthanide dopants (La, Ce, Nd, Sm, Dy, Er, Yb) were studied and the underlying mechanism was also discussed. Among these doping ions, Ce3+/Ce4+ doping CBN ceramics exhibits anomalous electrical properties. Impedance analysis was introduced to clarify the difference in electrical properties of lanthanide-doped CBN ceramics at high temperatures. As a result, the anomalous electrical properties are attributed to the extrinsic oxygen vacancies induced by the Ce doping. These results could assist to tailor the electrical properties of Aurivillius phase ceramics with lanthanide modifications. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] W/Ni codped BIT ceramics were sintered at low temperature. [•] W dopants decrease the degree of lattice distortion. [•] The increasing resistivity is attributed to alleviation of underbonding of Bi ions. [•] Oxygen vacancy is responsible for dielectric dispersion and DC electrical conduction. [•] The ferroelectricity of BITWN-12 ceramic was systematically studied. [ABSTRACT FROM AUTHOR]

Aurivillius phase (MnPr) co-doped CaBi2Nb2O9(CBN) piezoelectric ceramics were prepared using the conventional solid state method. The Curie-temperature (TC) of CBN-based ceramics decreased whereas the piezoelectric coefficient (d33) was improved with increasing of (MnPr) dopants. The experimental results showed that the (MnPr) ions could significantly improve the performance of CBN-based ceramics. 0.4%Mn + 1.0%Pr co-doped CBN ceramics had the best electric properties:d33=11.63 pC/N,kp= 7.4%,Qm= 4148,Kt= 22.4%,Np=2850 Hzm,Nt=2397 Hzm. [ABSTRACT FROM AUTHOR]

Highlights: [•] K+ modified LNN-based ceramics were synthesized by using mixed oxide routes. [•] K+ ions induced a phase transition from orthorhombic to tetragonal structure. [•] Dielectric behavior above T C was discussed and followed the Curie–Weiss law. [•] A set of material constants were determined by using a resonance–antiresonance method. [•] K+ dopants make a ‘softening’ effect on LNKNS-based piezoceramics. [ABSTRACT FROM AUTHOR]

Abstract: Aurivillius type (NaBi)0.5−x (LiCe) x Bi2Nb2O9 ceramics were prepared by the standard ceramics route. The single crystal structural ceramics were achieved for all compositions and lattice distortion was decreased by (LiCe) dopants. The temperature dependent dielectric properties revealed that all compositions possess a high Curie-temperature (>780 °C). A modified Curie–Weiss relationship is used to study the diffuseness behavior of a ferroelectric phase transition indicating the degree of diffuseness of NBN-based ceramics increased with (LiCe) modifications. The degradation of resistance implied a plausible model that Ce4+ ions entered into the B-site of the pseudo-perovskite structure and acted as acceptor doping. Further investigation demonstrated that both electrical conduction and dielectric relaxation processes were associated with the oxygen vacancies produced by the substitution of Nb5+ ions by the Ce4+ ions. [Copyright &y& Elsevier]

Aurivillius phase (Li,Ce) doped CaBi4Ti4O15(CBT) ceramics were prepared using the conventional solid state methods. The crystal structure and microstructure were determined by X-ray diffraction and scanning electron microscopy. It was found that the (Li,Ce) ions diffused into the A site of CBT's pseudo-perovskite structure and formed a single Aurivillius type structure. The Curie-temperature (TC) of CBT based ceramics decreased whereas the piezoelectric coefficient (d33) was improved with an increase of (Li,Ce) dopants. The detailed electrical properties for Ca0.85(LiCe)0.075Bi4Ti4O15ceramics in the high temperature region were determined using electrochemical impedance spectra. It was found that oxygen vacancies make a major contribution to both electrical conduction and dielectric relaxation. The ac conductivity was found to obey Jonscher's universal law. In addition, the physical nature of electrical conduction and dielectric relaxation was addressed in this paper. [ABSTRACT FROM AUTHOR]

(Li,Ce) modified Na0.5Bi2.5Nb2O9(NBN) Aurivillius type ceramics were synthesized by conventional mixed-oxide routes. The electrical properties of NBN-based ceramics were characterized in a wide range of frequency (100 Hz-1 MHz) and temperatures (500–750°C) by impedance spectrum techniques. It was found that the electrical conductivity and corresponding relaxation process were thermally activated, and the basic mechanisms were attributed to the hopping of oxygen vacancies in the grain interior. The decrease of resistivity and activation energy was indicative of the introduction of extra oxygen vacancies induced by (Li,Ce) dopants into NBN-based ceramics. In addition, the frequency dispersion of the dielectric behavior of NBN-based ceramics was owing to the space charge polarization at high temperature, as confirmed by impedance spectroscopies. [ABSTRACT FROM AUTHOR]

Abstract: (Na0.25K0.25Bi0.5)1− x (LiCe) x /2[] x /2Bi4Ti4O15 (NKBTLC-x) ceramics were prepared using the conventional solid state sintering method. X-ray diffraction results demonstrated that all samples have a single four-layered Aurivillius-type structure and the lattice distortion increases with increasing x, which induces the variation of Curie temperature (T C). Dielectric and electrical properties have been carried out over a wide range of frequency (100Hz–1MHz) and temperature (450–750°C) in order to elucidate the basic mechanism on the conduction and relaxation process. The relaxation process was explained by thermal activated hopping mechanism and shows an anomaly around the T C, temperature dependence of ac conductivity can be separated into three regions and the activation energy E a was calculated from the Arrhenius law. Moreover, the behavior of ac conductivity as a function of frequency was obeyed the universal power law and attributed to hopping conduction mechanism. [Copyright &y& Elsevier]

This study aims to systematically review published literature on heterosexual transmission among HIV discordant couples in China. We conducted a systematic review and random-effects meta-analysis of 32 published articles in both Chinese and English. The summarized overall HIV seroconversion rate among discordant couples in China is 1.2 per 100 person-years (95% CI 0.9–1.7/100 PY). The overall estimate for HIV prevalence through heterosexual transmission in discordant couples is 11.5% (95% CI 8.2%–15.2%) in China. In a stratified meta-analysis by region, Henan province showed an HIV seroconversion rate of 0.9/100 PY (95% CI 0.6–1.2/100 PY) and an HIV prevalence rate of 3.9% (95% CI 2.5–5.7%). Yunnan province showed an HIV seroconversion rate of 1.7/100 PY (95% CI 1.2–2.3/100 PY) and an HIV prevalence rate of 17.0% (95% CI 13.7–20.6%). Other provinces collectively showed a HIV seroconversion rate of 3.9/100 PY (95% CI 1.0–8.7/100 PY) and an HIV prevalence rate of 21.5% (95% CI 9.6–36.5%). In a stratified meta-analysis by time, the subgroup from 1994 to 2004 had a seroconversion rate of 3.9/100 PY (95% CI 1.0–8.7/100 PY) and the subgroup from 2005 to 2011 had a seroconversion rate of 1.1/100 PY (95% CI 0.8–1.5/100 PY). These data show that China's free national HIV prevention and treatment program has been successful at limiting transmission in discordant couples. Because heterosexual transmission is now the dominant method of HIV transmission in China, it is important to understand seroconversion and prevalence rates in discordant couples to develop more effective prevention and treatment programs. [ABSTRACT FROM PUBLISHER]

Abstract: Sb5+-doped (NaBi)0.38(LiCe)0.05[]0.14Bi2Nb2O9 (represented as NBNLCS-x, where [] represents A-site vacancies) ceramics were prepared by the conventional solid-state route. The ceramics well sintered to approach ∼98.5% theoretical density and the tetragonality of crystal structure increased with Sb5+ additions. However, the Curie temperature (T C) and the piezoelectric coefficient (d 33) of Sb5+-modified ceramics gradually decreased. The 3mol% Sb5+-doped samples exhibited optimum properties with a d 33 value of ∼22pC/N planar electromechanical coupling factor (k p) of ∼11.2% and relatively high T C of ∼765°C. These results indicate that NBNLCS-x material is a promising candidate for high-temperature piezoelectric applications. [Copyright &y& Elsevier]

Antimony modified (Na0.5K0.5)NbO3 lead-free piezoelectric ceramics were prepared by conventional electroceramic process. The role of Sb5+ in (Na0.5K0.5)NbO3 perovskite structure B site was discussed. The degree of crystalline structural symmetry increased with Sb5+ content increasing, changing from orthorhombic to pseudocubic. As a result, the thermal stability of crystalline structure and ferroelectric properties of (Na0.5K0.5)NbO3 ceramics decreased. (Na0.5K0.5)NbO3 ceramics with 3 mol% Sb5+ displayed enhanced piezoelectric properties, the piezoelectric constant d33 was 144 pC/N, planar electromechanical coupling coefficient kp was 49%, mechanical quality factor Qm was 160, and Tc = 344°C, respectively. [ABSTRACT FROM AUTHOR]

Abstract: This paper first applies the sequential cluster method to set up the classification standard of infectious disease incidence state based on the fact that there are many uncertainty characteristics in the incidence course. Then the paper presents a weighted Markov chain, a method which is used to predict the future incidence state. This method assumes the standardized self-coefficients as weights based on the special characteristics of infectious disease incidence being a dependent stochastic variable. It also analyzes the characteristics of infectious diseases incidence via the Markov chain Monte Carlo method to make the long-term benefit of decision optimal. Our method is successfully validated using existing incidents data of infectious diseases in Jiangsu Province. In summation, this paper proposes ways to improve the accuracy of the weighted Markov chain, specifically in the field of infection epidemiology. [ABSTRACT FROM AUTHOR]

Tumor–immune system interactions are very complicated, being highly nonlinear and not well understood. A large number of tumors can potentially weaken the immune system through various mechanisms such as secreting cytokines that suppress the immune response. In this paper, we propose a tumor–immune system interaction model with a nonmonotonic immune response function and adoptive cellular immunotherapy (ACI). The model has a tumor-free equilibrium and at most three tumor-presence equilibria (low, moderate and high ones). The stability of all equilibria is studied by analyzing their characteristic equations. The consideration of nonmonotonic immune response results in a series of bifurcations such as the saddle-node bifurcation, transcritical bifurcation, Hopf bifurcation and Bogdanov–Takens bifurcation. In addition, numerical simulation results show the coexistence of periodic orbits and homoclinic orbits. Interestingly, along with various bifurcations, we also found two bistable scenarios: the coexistence of a stable tumor-free as well as a high-tumor-presence equilibrium and the coexistence of a stable-low as well as a high-tumor-presence equilibrium, which can show symmetric and antisymmetric properties in a range of model parameters and initial cell concentrations. The new findings indicate that under ACI, patients can possibly reach either a stable tumor-free state or a low-tumor-presence state in the presence of nonmonotonic immune response once the immune system is activated. [ABSTRACT FROM AUTHOR]

Diagnostic delay for TB infected individuals and the lack of TB vaccines for adults are the main challenges to achieve the goals of WHO by 2050. In order to evaluate the impacts of diagnostic delay and vaccination for adults on prevalence of TB, we propose an age-structured model with latent age and infection age, and we incorporate Mycobacterium TB in the environment and vaccination into the model. Diagnostic delay is indicated by the age of infection before receiving treatment. The threshold dynamics are established in terms of the basic reproduction number R 0 . When R 0 < 1 , the disease-free equilibrium is globally asymptotically stable, which means that TB epidemic will die out; When R 0 = 1 , the disease-free equilibrium is globally attractive; there exists a unique endemic equilibrium and the endemic equilibrium is globally attractive when R 0 > 1 . We estimate that the basic reproduction number R 0 = 0.5320 (95% CI (0.3060, 0.7556)) in Jiangsu Province, which means that TB epidemic will die out. However, we find that the annual number of new TB cases by 2050 is 1,151 (95%CI: (138, 8,014)), which means that it is challenging to achieve the goal of WHO by 2050. To this end, we evaluate the possibility of achieving the goals of WHO if we start vaccinating adults and reduce diagnostic delay in 2025. Our results demonstrate that when the diagnostic delay is reduced from longer than four months to four months, or 20% adults are vaccinated, the goal of WHO in 2050 can be achieved, and 73,137 (95%CI: (23,906, 234,086)) and 54,828 (95%CI: (15,811, 206,468)) individuals will be prevented from being infected from 2025 to 2050, respectively. The modeling approaches and simulation results used in this work can help policymakers design control measures to reduce the prevalence of TB. [ABSTRACT FROM AUTHOR]

Abstract: Aurivillius type (LiCePr)-multidoped CaBi2Nb2O9 ceramics were prepared using the conventional mixed oxides route. The effects of the (LiCePr) additives on the structure and dielectric properties were studied. The piezoelectricity was significantly improved by the incorporation of (LiCePr) dopants. The Ca0.9(Li0.5Ce0.25Pr0.25)0.1Bi2Nb2O9 (CBN–LCP10) ceramics possess the optimum properties, and the d 33, k p and T C values were found to be ∼17.3pC/N, 7.8% and ∼939°C, respectively. The thermal depoling behavior and electromechanical properties at elevated temperature were studied in detail. Both results demonstrate that CBN–LCP10 ceramics possess a stable piezoelectricity in a wide temperature range, making CBN-based ceramics promising for high temperature applications. [Copyright &y& Elsevier]

Background: Severe fever with thrombocytopenia syndrome (SFTS) was listed as one of the most severe infectious disease by world health organization in 2017. It can mostly be transmitted by tick bite, while human-to-human transmission has occurred on multiple occasions. This study aimed to explore the epidemiological and clinical characteristics and make risk analysis of SFTS human-to-human transmission. Methods: Descriptive and spatial methods were employed to illustrate the epidemiological and clinical characteristics of SFTS human-to-human transmission. The risk of SFTS human-to-human transmission was accessed through secondary attack rate (SAR) and basic reproductive number (R0). Logistic regression analysis was used to identify the associated risk factors. Results: A total of 27 clusters of SFTS human-to-human transmission were reported in China and South Korea during 1996–2019. It mainly occurred among elder people in May, June and October in central and eastern China. The secondary cases developed milder clinical manifestation and better outcome than the index cases. The incubation period was 10.0 days (IQR:8.0–12.0), SAR was 1.72%-55.00%, and the average R0 to be 0.13 (95%CI:0.11–0.16). Being blood relatives of the index case, direct blood/bloody secretion contact and bloody droplet contact had more risk of infection (OR = 6.35(95%CI:3.26–12.37), 38.01 (95%CI,19.73–73.23), 2.27 (95%CI,1.01–5.19)). Conclusions: SFTS human-to-human transmission in China and South Korea during 1996–2019 had obvious spatio-temporal distinction. Ongoing assessment of this transmission risk is crucial for public health authorities though it continues to be low now. Author summary: This study is first to explore the epidemiological and clinical characteristics of SFTS human-to-human transmission. We found SFTS human-to-human transmission had obvious characteristic temporal and spatial distinction, which mainly occurred among elder people in May, June and October in the central and eastern China. The secondary cases developed milder clinical manifestation and better outcome than the index cases. The incubation period was 10.0 days (IQR:8.0–12.0). The risk of SFTS human-to-human transmission continues to be low, with the secondary attack rate (SAR) among humans was 1.72%-55.00% and basic reproductive number (R0) to be 0.13 (95%CI:0.11–0.16). Being blood relatives of the index case, direct blood/bloody secretion contact and bloody droplet contact had more risk of acquiring infection. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we propose an SIRS influenza model with general incidence rate to describe disease transmission in a heterogenous environment. The basic reproduction number R 0 is defined for the model, which can be used to govern the threshold dynamics of influenza disease: if R 0 < 1 , the unique disease-free equilibrium is globally asymptotic stable and there is no endemic equilibrium, while R 0 > 1 , there is at least one endemic equilibrium and the disease is uniformly persistent. Epidemiologically, we find that the spatial heterogeneity can enhance the infectious risk of the influenza and thus, in order to control the spread of the influenza, we must increase the recovery rate and the spatial heterogeneity in the transmission rate, or people should change their travelling plan and stay at home to reduce the value of the diffusion coefficient. [ABSTRACT FROM AUTHOR]

Objective: To investigate the efficacy and safety of Tui Na for treating spasticity of the upper limbs of stroke patients. Design: A prospective, multicenter, blinded, randomized controlled intervention study. Subjects: Stroke patients with upper limb spasticity who were treated between December 2013 and February 2017 in 16 participating institutions in China were randomly assigned to receive either Tui Na plus conventional rehabilitation (Tui Na group, n = 222,) or conventional rehabilitation only (control group, n = 222). Methods: Eligible adult patients (aged 18–75 years) were enrolled 1–12 months after stroke and randomly allocated in a 1:1 ratio to the two groups. Outcome assessors were blinded to treatment allocation. Muscle tone in the spastic muscles was evaluated using the Modified Ashworth Scale (MAS), and the primary endpoint was the change in MAS score over 4 weeks of treatment. Results: Among patients who had experienced stroke 1–3 months before treatment, the Tui Na group experienced significantly greater reductions in MAS scores for three muscle groups than did the control group after 4 weeks of treatment. These improvements were sustained at the 3‐ and 6‐month follow‐ups. However, among patients who suffered from stroke 4–6 months and 7–12 months before treatment, the change in MAS with treatment did not differ significantly between those who did and those who did not receive Tui Na. No Tui Na‐related adverse events during treatment were reported the groups. Conclusion: Tui Na was effective and safe for alleviating poststroke spasticity within 1–3 months after stroke onset. [ABSTRACT FROM AUTHOR]

High Curie-temperature CaBi 2 Nb 2- x Zr x O 9 (abbreviated as CBNZr-100 x ) ceramics were prepared by a conventional solid-state sintering method. The effects of Zr 4+ doping contents and sintering temperature on the microstructure and electrical properties of CBNZr-100 x ceramics were investigated. Single-phase CBNZr-100 x ceramics are determined by the X-ray diffraction and the calculated cell volume decreases with increasing Zr contents. Impedance analysis was conducted in wide ranges of temperature and frequency region. Results show that the introduction of Zr 4+ ions could improve the electrical properties for both grain and grain boundary and subsequently increases the breakdown voltage of CBNZr-100 x ceramics. Meanwhile, the Curie temperature of CBNZr-100 x  increases and the dielectric loss decreases with increasing Zr contents. The sintering temperature obviously affects the grain morphology of CBNZr-3 ceramics but its effects on the electrical properties are less obvious than those of Zr contents on CBNZr-100 x  ceramics, indicating that the ordered structure of the grain inside of CBNZr-3 ceramics changes little with different sintering temperature. However, the Curie temperature and the resistance for grain boundaries of CBNZr-100 x  ceramics decrease with increasing sintering temperature, which is probably because of the increasing impurities and defects in grain boundaries. [ABSTRACT FROM AUTHOR]

Different type doped CaBi 2 Nb 2 O 9 (CBN) ceramics were prepared by a conventional solid state sintering method. The number of oxygen vacancies were decreased or increased by the introduction of W 6+ and Ti 4+ doping in CBN ceramics. The influence of W 6+ , Ti 4+ and W 6+ /Ti 4+ dopants on the microstructures and electrical properties of CBN-based ceramics was investigated. The voids and spherical morphology in the SEM image of W, Ti co-doped ceramics indicate that W, Ti co-doping could change the microstructure of CBN-based ceramics. Impedance analysis results show that the electrical properties of CBN-based ceramics have a close relationship with the number of oxygen vacancies. W doping and W, Ti co-doping decrease the oxygen vacancies, as a result, the resistance and piezoelectric properties were increased and the frequency dispersion of dielectric properties were restrained. [ABSTRACT FROM AUTHOR]

(Li, Ce, and Nd)-multidoped CaBi 2 Nb 2 O 9 (CBN) Aurivillius phase ceramics were prepared via a conventional solid-state sintering route. The crystal structure including bond lengths and bond angles, microstructure, dielectric constant, DC resistivity, and piezoelectric properties were systematically investigated. Rietveld-refinements of X-ray results indicated that small quantity of (Li, Ce, Nd) doping (< 2.5 mol%) increases orthorhombic distortion, because of the smaller ionic radii of doping ions. However, orthorhombic distortion obviously decreased with increasing (Li, Ce, Nd) doping concentration from 5 to 25 mol%. The replacement of asymmetric A-site Bi 3+ with 6s2 lone pair electrons by symmetric Li + , Ce 3+ and Nd 3+ ions decreased the orthorhombic distortion. The morphologies and electrical properties of sintered ceramics were tailored by the introducing (Li, Ce, Nd) multi-dopants. The improvement of piezoelectric properties of modified-CBN ceramics were attributed to decreasing grain sizes and morphotropic phase boundary (MPB). Ca 0.85 (Li 0.5 Ce 0.25 Nd 0.25 ) 0.15 Bi 2 Nb 2 O 9 (CBNLCN-15) ceramics had optimum properties, and d 33 and T c values were found to be ~ 13.1 pC/N and ~ 900 °C, respectively. [ABSTRACT FROM AUTHOR]

Background Cytomegalovirus (CMV) infection is associated with increased mortality in persons with HIV (PWH). It is less clear whether CMV infection is still associated with mortality when routinely screened and adequately treated. Methods This retrospective cohort study recruited 1003 hospitalized adults with HIV with CD4 cell counts <200 cells/μL from May 2017 to June 2021. Blood CMV DNA was routinely measured and CMV DNAemia was treated if end-organ disease occurred. CMV viral load was categorized into below the limit of quantification (BLQ; <500 IU/mL), low viral load (LVL; 500–10 000 IU/mL), and high viral load (HVL; ≥10 000 IU/mL) groups. We compared the 182-day all-cause mortality among different groups. Results The median (IQR) CD4 cell count of patients was 33 (13–84) cells/μL. The prevalence of CMV DNAemia was 39.8% (95% CI: 36.7–42.9%) and was significantly associated with CD4 cell count. The 182-day all-cause mortality was 9.9% (95% CI: 8.0–11.7%). Univariable analysis showed that, compared with BLQ, LVL and HVL were associated with 1.73-fold and 3.81-fold increased risks of mortality, respectively (P =.032 and P <.001). After adjustment for predefined confounding factors, HVL but not LVL was still associated with increased risk of mortality (adjusted hazard ratio: 2.63; 95% CI: 1.61–4.29; P <.001). However, for patients on effective antiretroviral therapy, the impact of HVL on 182-day mortality was not significant (P =.713). Conclusions High CMV viral load in hospitalized PWH was associated with higher mortality, even when identified early by screening. Optimalization of the management for those patients needs to be explored in future studies. [ABSTRACT FROM AUTHOR]

We develop a stochastic HIV model by integrating drug adherence into a pharmacokinetic model and by coupling a pharmacodynamic model with a viral dynamic model. Numerical simulations show that the proposed model can generate viral blips, which have been observed in HIV patients receiving suppressive antiretroviral therapy. We calculate the probability density function of infected CD 4 + T cells by developing the generalized density evolution equation. We fit the model to the clinical data of four HIV patients exhibiting viral blips. The results demonstrate that poor drug adherence can be a reason explaining the occurrence of viral blips in treated HIV patients. We also find that viral dynamics are sensitive to drug-adherence parameters, which have a significant impact on the frequency and amplitude of viral blips. The modeling and methods can be applied to the study of long-term therapy of other chronic diseases in which drug adherence might also be an issue. [ABSTRACT FROM AUTHOR]

Tuberculosis was ranked No. 3 among 29 types of infectious diseases in January 2022 of Jiangsu Province, in the southeast of China, and it has strong seasonality whose incidence rate has been high in springs and low in winters. This comprehensive study extends the spreading dynamics to the control strategies of TB in Jiangsu Province with time‐varying transmission rate, which is the first one in this type. The periodic transmission rate is incorporated to the classic SEIR model with susceptible, latent, infectious, and recovered compartments. The analysis shows that when the basic reproduction number R0$$ {R}_0 $$ is less than one, the epidemic will eventually disappear but, if R0$$ {R}_0 $$ is larger than one, the disease may persist with a periodic solution. The R0$$ {R}_0 $$ value of Jiangsu TB is calculated as 1.297. In addition, the model predicts that the epidemic will not disappear over time and there will be a major outbreak after certain years. To eradicate TB, this work introduces three control strategies on susceptible, latent, and infectious populations. It turns out that the optimal control solutions can reduce the incidence rate in 2035 by 90% from 2015, the goal of World Health Organization. Simultaneously, we find that the optimal controls have the same seasonality as the transmission rate. This indicates that Jiangsu Province needs to invest more control efforts in springs than in winters. In addition, the cost of control strategies is analyzed in terms of the unit cost, total cost, and incremental cost‐effectiveness. Summarizing all results, we recommend targeting the latent patients, or both latent and infectious individuals, with the transmission rate‐synchronized control strength as the most effective control strategy, to mitigate or even eradicate TB disease in Jiangsu Province. [ABSTRACT FROM AUTHOR]

Hand-foot-mouth disease (HFMD) has spread widely in mainland China and exhibited an increasing trend in prevalence in recent years with serious consequences for child health. The HFMD virus can survive for a long period outside the host in suitable conditions, and hence indirect transmission via free-living virus in the environment can not be ignored. We then propose a novel mathematical model to represent both direct transmission and indirect transmission, and also periodic transmission and vaccination rates. We obtain a threshold value, the basic reproduction number which governs whether nor not HFMD infection dies out by applying the persistence theory of periodic systems. Theoretical results indicate that the disease goes to extinction if the basic reproduction number is less than unity and otherwise the disease uniformly persists. By fitting the proposed model to reported data on symptomatic cases of endemic HFMD in mainland China we estimate the basic reproduction number as 1.74. Numerical simulations show that the asymptotic infected individuals and contaminated environments are essential factors substantially contributing to HFMD new infections, and hence they should not be ignored. Sensitivity analysis indicates that the basic reproduction number is sensitive to the transmission rate induced by asymptomatic infectious individuals, vaccination rate and parameters associated with contaminated environments such as the indirect transmission rate and the rate of clearance. Our finding suggests that enhancing vaccination strategy and the frequent cleaning of the environment and enhancing individual sanitation (e.g. regular hand-washing) are effective measures in controlling HFMD infections. [ABSTRACT FROM AUTHOR]

• The association between temperature and influenza was nonlinear, and the contribution of low temperatures to influenza epidemics was relatively large. • The association between temperature and influenza activity varies in different regions, suggesting that influenza prevention and control policies need to be tailored to local conditions. • The threshold temperatures for an early warning of serious influenza outbreaks were −24.3 ℃ in northeast region, 16.6 ℃ in northwest region, and 1–10 ℃ in the other regions of China. Temperature affects influenza transmission; however, currently, limited evidence exists about its effect in China at the national and city levels as well as how temperature can be integrated into influenza interventions. Meteorological, pollutant, and influenza data from 201 cities in mainland China between 2013 and 2018 were analyzed at both the city and national levels to investigate the relationship between temperature and influenza prevalence. We examined the impact of temperature on the time-varying reproduction number (R t) using generalized additive quasi-Poisson regression models combined with the distributed lag nonlinear model. Threshold temperatures were determined for seven regions based on the early warning threshold of serious influenza outbreaks, set at R t = 1.2. A multivariate random-effects meta -analysis was employed to assess region-specific associations. The excess risk (ER) index was defined to investigate the correlation between R t and temperature, modified based on seasonal and regional characteristics. At the national level and in the central, northern, northwestern, and southern regions, temperature was found to be negatively correlated with relative risk, whereas the shapes of the data curves for the eastern, southwestern, and northeastern regions were not well defined. Low temperatures had an observable effect on influenza prevalence; however, the effects of high temperatures were not obvious. At an R t of 1.2, the threshold temperatures for reaching a warning for serious influenza outbreaks were − 24.3 °C in the northeastern region, 16.6 °C in the northwestern region, and between 1℃ and 10 °C in other regions. The study findings revealed that temperature had a varying effect on influenza transmission trends (R t) across different regions in China. By identifying region-specific temperature thresholds at R t = 1.2, more effective early warning systems for influenza outbreaks could be tailored. These findings emphasize the significance of the region-specific adaptation of influenza prevention and control measures. [ABSTRACT FROM AUTHOR]

Can a non-invasive embryo transfer strategy provide a reference for embryo selection to be established? Chromosome sequencing of 345 paired blastocyst culture medium and whole blastocyst samples was carried out and a non-invasive embryo grading system was developed based on the random forest machine learning algorithm to predict blastocyst ploidy. The system was validated in 266 patients, and a blinded prospective observational study was conducted to investigate clinical outcomes between machine learning-guided and traditional non-invasive preimplantation genetic testing for aneuploidy (niPGT-A) analyses. Embryos were graded as A, B or C according to their euploidy probability levels predicted by non-invasive chromosomal screening (NICS). Higher live birth rate was observed in A- versus C-grade embryos (50.4% versus 27.1%, P = 0.006) and B- versus C-grade embryos (45.3% versus 27.1%, P = 0.022) and lower miscarriage rate in A- versus C-grade embryos (15.9% versus 33.3%, P = 0.026) and B- versus C-grade embryos (14.3% versus 33.3%, P = 0.021). The embryo utilization rate was significantly higher through the machine learning strategy than the conventional dichotomic judgment of euploidy or aneuploidy in the niPGT-A analysis (78.8% versus 57.9%, P < 0.001). Better outcomes were observed in A- and B-grade embryos versus C-grade embryos and higher embryo utilization rates through the machine learning strategy compared with traditional niPGT-A analysis. A machine learning guided embryo grading system can be used to optimize embryo selection and avoid wastage of potential embryos. [ABSTRACT FROM AUTHOR]

Ca(Li,Ce)BiNbWO ( x = 0.01-0.06) high-temperature piezoceramics were prepared by a conventional solid-state sintered method, and effects of W content on their piezoelectric properties were studied. All samples possess a pure Aurivillius-type structure, showing that Li, Ce, and W dopants have well diffused into the CaBiNbO lattice to form a solid solution. The doping with W slightly decreases the Curie temperature ( T) of the ceramics. In addition, the excellent electrical properties (e.g., d ~ 16.1 pC/N, k ~ 9.58 %, Q ~ 4,767) and a high Curie temperature (e.g., T ~ 925 °C) are simultaneously obtained in the ceramics with x = 0.04, together with an enhanced thermal stability of <900 °C. As a result, the investigated material system provides the promising potential applications in ultra-high-temperature environments. [ABSTRACT FROM AUTHOR]

Background: Great achievements have been achieved by free antiretroviral therapy (ART). A rapid and accurate prediction of survival in people living with HIV/AIDS (PLHIV) is needed for effective management. We aimed to establish an effective prognostic model to forecast the survival of PLHIV after ART.Methods: The participants were enrolled from a follow-up cohort over 2003-2019 in Nanjing AIDS Prevention and Control Information System. A nested case-control study was employed with HIV-related death, and a propensity-score matching (PSM) approach was applied in a ratio of 1:4 to allocate the patients. Univariable and multivariable Cox proportional hazards analyses were performed based on the training set to determine the risk factors. The discrimination was qualified using the area under the curve (AUC) and concordance index (C-Index). The nomogram was calibrated using the calibration curve. The clinical benefit of prognostic nomogram was assessed by decision curve analysis (DCA).Results: Predictive factors including CD4 cell count (CD4), body mass index (BMI) and hemoglobin (HB) were determined and incorporated into the nomogram. In the training set, AUC and C-index (95% CI) were 0.831 and 0.798 (0.758, 0.839), respectively. The validation set revealed a good discrimination with an AUC of 0.802 and a C-index (95% CI) of 0.786 (0.681, 0.892). The calibration curve also exhibited a high consistency in the predictive power (especially in the first 3 years after ART initiation) of the nomogram. Moreover, DCA demonstrated that the nomogram was clinically beneficial.Conclusion: The nomogram is effective and accurate in forecasting the survival of PLHIV, and beneficial for medical workers in health administration. [ABSTRACT FROM AUTHOR]

Objective: To predict the trend of AIDS in specific age groups and to determine the objective population for AIDS screening, this study explored the three transmission routes and characterized each patient group using the APC model based on the whole, local, and immigrant populations in Zhejiang, China.Methods: The data recruited in this paper was obtained from the national Comprehensive AIDS Prevention and Control Information System - Antiviral Therapy Management database and the Chinese Disease Prevention and Control Information System and the Statistical Yearbook of Zhejiang, China. An APC model was used to estimate the impact of age, period, and cohort on the incidence of AIDS, as well as to predict the AIDS incidence in specific age groups based on different sexes with different transmission routes.Results: The AIDS incidence peaked in males aged 20-35 years; the incidence of males was higher than that of females due to the impact of period; obvious cohort effect was observed among the immigrants. In the whole and local populations, the incidences of males in all age groups and females in both the 35-year-old group and the whole age group were predicted to increase sharply in 5 years. In the immigrant population, the AIDS incidences in both sexes in all age groups were expected to increase significantly in 5 years. Under the influence of period, the incidence of AIDS via homosexual transmission in the whole population and the local population increased and remained stable after 2015. At the same time, the incidence of AIDS transmitted by homosexual and heterosexual routes in the immigrants also showed an increasing trend.Conclusions: The results elucidate that there are sex differences in AIDS incidence, and the incidence of AIDS through various transmission routes in all groups is predicted to exhibit an upward trend in the 5 years to come. Effective intervention strategies should be developed and implemented by the public health departments in Zhejiang to control the epidemic of AIDS. [ABSTRACT FROM AUTHOR]

• We developed a mobility network model for spatial epidemics. • The second outbreak occurred approximately on March 1, 2020. • By March 15, 2020, the cumulative cases increased by 70.6% without a travel ban. • The increase of cumulative cases is mainly caused by intra-province travel. • The strict travel ban successfully prevented a severe secondary wave in China. The ongoing COVID-19 pandemic expanded its geographic distribution through the movement of humans and caused subsequent local outbreaks. Hence, it is essential to investigate how human mobility and travel ban affect the transmission and spatial spread while minimizing the impact on social activities and national economics. We developed a mobility network model for spatial epidemics, explicitly taking into account time-varying inter-province and inner-province population flows, spatial heterogeneity in terms of disease transmission, as well as the impact of media reports. The model is applied to study the epidemic of the dynamic network of 30 provinces of mainland China. The model was calibrated using the publicly available incidence and movement data. We estimated that the second outbreak occurred approximately on February 24, 2020, and the cumulative number of cases as of March 15, 2020, increased by 290.1% (95% CI: (255.3%, 324.9%)) without a travel ban in mainland China (excluding Hubei and Tibet). We found that intra-province travel contributes more to the increase of cumulative number of cases than inter-province travel. Our quantitative and qualitative research results suggest that the strict travel ban has successfully prevented a severe secondary outbreak in mainland China, which provides solutions for many countries and regions experiencing secondary outbreaks of COVID-19. [ABSTRACT FROM AUTHOR]

Objective. To establish a machine learning model for identifying patients coinfected with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) through two sexual transmission routes in Jiangsu, China. Methods. A total of 14197 HIV cases transmitted by homosexual and heterosexual routes were recruited. After data processing, 12469 cases (HIV and HBV, 1033; HIV, 11436) were left for further analysis, including 7849 cases with homosexual transmission and 4620 cases with heterosexual transmission. Univariate logistic regression was used to select variables with significant P value and odds ratio for multivariable analysis. In homosexual transmission and heterosexual transmission groups, 10 and 6 variables were selected, respectively. For identifying HIV individuals coinfected with HBV, a machine learning model was constructed with four algorithms, including Decision Tree, Random Forest, AdaBoost with decision tree (AdaBoost), and extreme gradient boosting decision tree (XGBoost). The detective value of each variable was calculated using the optimal machine learning algorithm. Results. AdaBoost algorithm showed the highest efficiency in both transmission groups (homosexual transmission group: accuracy = 0.928 , precision = 0.915 , recall = 0.944 , F − 1 = 0.930 , and AUC = 0.96 ; heterosexual transmission group: accuracy = 0.892 , precision = 0.881 , recall = 0.905 , F − 1 = 0.893 , and AUC = 0.98). Calculated by AdaBoost algorithm, the detective value of PLA was the highest in homosexual transmission group, followed by CR, AST, HB, ALT, TBIL, leucocyte, age, marital status, and treatment condition; in the heterosexual transmission group, the detective value of PLA was the highest (consistent with the condition in the homosexual group), followed by ALT, AST, TBIL, leucocyte, and symptom severity. Conclusions. The univariate logistics regression combined with the AdaBoost algorithm could accurately screen the risk factors of HBV in HIV coinfection without invasive testing. Further studies are needed to evaluate the utility and feasibility of this model in various settings. [ABSTRACT FROM AUTHOR]

We investigated an outbreak of COVID‐19 infection, which was traced back to a bathing pool at an entertainment venue, to explore the epidemiology of the outbreak, understand the transmissibility of the virus and analyse the influencing factors. Contact investigation and management were conducted to identify potential cases. Epidemiological investigation was carried out to determine the epidemiological and demographic characteristics of the outbreak. We estimated the secondary attack rate (SAR), incubation time and time‐dependent reproductive number (Rt) and explored the predisposing factors for cluster infection. The incubation time was 5.4 days and the serial interval (SI) was 4.4 days, with the rate of negative‐valued SIs at 24.5%. The SAR at the bathing pool (3.3%) was relatively low due to its high temperature and humidity. The SAR was higher in the colleagues' cluster (20.5%) than in the family cluster (11.8%). Super‐spreaders had a longer isolation delay time (p =.004). The Rt of the cluster decreased from the highest value of 3.88 on January 27, 2020 to 1.22 on February 6. Our findings suggest that the predisposing factors of the outbreak included close contact with an infected person, airtight and crowded spaces, temperature and humidity in the space and untimely isolation of patients and quarantine of contacts at the early stage of transmission. Measures to reduce the risk of infection at these gatherings and subsequent tracking of close contacts were effective. [ABSTRACT FROM AUTHOR]

Background: In infectious disease transmission dynamics, the high heterogeneity in individual infectiousness indicates that few index cases generate large numbers of secondary cases, which is commonly known as superspreading events. The heterogeneity in transmission can be measured by describing the distribution of the number of secondary cases as a negative binomial (NB) distribution with dispersion parameter, k. However, such inference framework usually neglects the under-ascertainment of sporadic cases, which are those without known epidemiological link and considered as independent clusters of size one, and this may potentially bias the estimates.Methods: In this study, we adopt a zero-truncated likelihood-based framework to estimate k. We evaluate the estimation performance by using stochastic simulations, and compare it with the baseline non-truncated version. We exemplify the analytical framework with three contact tracing datasets of COVID-19.Results: We demonstrate that the estimation bias exists when the under-ascertainment of index cases with 0 secondary case occurs, and the zero-truncated inference overcomes this problem and yields a less biased estimator of k. We find that the k of COVID-19 is inferred at 0.32 (95%CI: 0.15, 0.64), which appears slightly smaller than many previous estimates. We provide the simulation codes applying the inference framework in this study.Conclusions: The zero-truncated framework is recommended for less biased transmission heterogeneity estimates. These findings highlight the importance of individual-specific case management strategies to mitigate COVID-19 pandemic by lowering the transmission risks of potential super-spreaders with priority. [ABSTRACT FROM AUTHOR]

To determine the short- (4 weeks) and long-term (6 month) effectiveness of Tibetan medicated bathing therapy in patients with post-stroke limb spasticity. Prospective, blinded, randomized controlled trial. Post-stroke patients with limb spasticity were recruited between December 2013 and February 2017 and randomly assigned 1:1 to a control group that received conventional rehabilitation (n = 222) or an experimental group that received Tibetan medicated bathing therapy in combination with conventional rehabilitation (n = 222). All patients received conventional rehabilitation. In addition, the experimental group received Tibetan medicated bathing therapy. The interventions were conducted 5 times per week for 4 weeks. The primary endpoint was changes from baseline after 4 weeks of therapy in muscle tone in the spastic muscles (elbow flexors, wrist flexors, finger flexors, knee extensors, ankle plantar flexors), as measured by the Modified Ashworth Scale (MAS). The mean change from baseline after 4 weeks of therapy in the MAS score for the elbow flexors (P =.017), wrist flexors (P <.001), and ankle plantar flexors (P <.001) was significantly greater in patients in the experimental group compared to the control group. The benefit was maintained for 3 muscle groups (elbow flexors P <.001, wrist flexors P =.001, and ankle plantar flexors P <.001) and 6 months (elbow flexors P <.001, wrist flexors P =.002, and ankle plantar flexors P <.001) after therapy. All adverse events were mild, and no serious adverse reactions to Tibetan medicated bathing therapy were recorded. Tibetan medicated bathing therapy, in combination with conventional rehabilitation, has potential as a safe, effective treatment for the alleviation of post-stroke upper limb spasticity. Tibetan medicated bathing therapy was most advantageous for patients who had a baseline muscle tone score of 1+ to 2 on the MAS in the affected limb and recent onset of stroke (duration of the disease of 1-3 months). [ABSTRACT FROM AUTHOR]

Keywords: coagulation parameter; D-dimer; COVID-19; anticoagulant treatment EN coagulation parameter D-dimer COVID-19 anticoagulant treatment e24 e27 4 07/01/20 20200701 NES 200701 Since December 2019, the severity of the coronavirus disease 2019 (COVID-19) pandemic has been escalating.[1] Coagulopathy is common in critically ill patients with COVID-19.[2] Systemic microvascular thrombosis may occur in most deaths, and was corroborated by a recent autopsy.[3] However, less is known about the coagulation parameter D-dimer in the progression of COVID-19. Moreover, it is well documented that abnormal D-dimer is helpful in indicating deep venous thrombosis in cardiovascular diseases.[8] Thus, we analysed the correlation between D-dimer level with clinical prognosis in patients with and without cardiovascular disease. Anticoagulant treatment may benefit severe COVID-19 patients, especially those without cardiovascular disease. [Extracted from the article]

We depicted the epidemiological characteristics of infectious diarrhoea in Jiangsu Province, China. Generalized additive models were employed to evaluate the age-specific effects of etiological and meteorological factors on prevalence. A long-term increasing prevalence with strong seasonality was observed. In those aged 0–5 years, disease risk increased rapidly with the positive rate of virus (rotavirus, norovirus, sapovirus, astrovirus) in the 20–50% range. In those aged > 20 years, disease risk increased with the positive rate of adenovirus and bacteria (Vibrio parahaemolyticus, Salmonella, Escherichia coli, Campylobacter jejuni) until reaching 5%, and thereafter stayed stable. The mean temperature, relative humidity, temperature range, and rainfall were all related to two-month lag morbidity in the group aged 0–5 years. Disease risk increased with relative humidity between 67–78%. Synchronous climate affected the incidence in those aged >20 years. Mean temperature and rainfall showed U-shape associations with disease risk (with threshold 15 °C and 100 mm per month, respectively). Meanwhile, disease risk increased gradually with sunshine duration over 150 hours per month. However, no associations were found in the group aged 6–19 years. In brief, etiological and meteorological factors had age-specific effects on the prevalence of infectious diarrhoea in Jiangsu. Surveillance efforts are needed to prevent its spread. [ABSTRACT FROM AUTHOR]

Purpose: To explore the feasibility of assessing the cancerization risk of oral potentially malignant disorders (OPMD) through a clinical risk model combined with autofluorescence and brush biopsy with DNA-image cytometry. Methods: We collected the baseline clinical data of 269 patients; then, performed autofluorescence, brush biopsy with DNA-image cytometry and histopathological examination. Then, we obtained the significant factors by univariate logistic analysis, constructed the clinical risk model by multiple logistic regression and selected the optimal cutoff value according to the maximum Youden index. Finally, we calculated the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the clinical risk score ≥ cutoff value, autofluorescence and brush biopsy with DNA-image cytometry, and plotted the receiver-operating characteristic (ROC) curves and decision curve analysis (DCA). Results: The clinical risk model is represented by the formula: 1 × gender + 1.6 × age group + 1 × lesion site + 1.4 × local stimulus + 1.5 × drink. The area under the curve (AUC) was 0.83, and the optimal cutoff score was 3. The AUC indicated that the clinical risk score ≥ 3 (0.74) and autofluorescence (0.77) had a certain diagnostic values, while brush biopsy with DNA-image cytometry (0.92) displayed a good value. Besides, the DCA showed that all three tests had clinical significance. Conclusions: The cancerization risk of patients can be assessed by the clinical risk model combined with sequence application of autofluorescence and brush biopsy with DNA-image cytometry, to decide whether histopathological examination or other intervention measures should be selected. [ABSTRACT FROM AUTHOR]

Abstract In this paper, we investigate the effect of the spatial heterogeneity on the extinction and persistence of the Zika virus (ZIKV) further. We define the basic reproduction number R 0 and prove that R 0 can be used to govern the threshold dynamics of the ZIKV: if R 0 < 1 , the unique disease-free equilibrium is globally asymptotic stable and the ZIKV will die out, while if R 0 > 1 , there is at least one endemic equilibrium and the ZIKV will persist uniformly. Via numerical simulations, we show the evolution of the spatial distribution of infected people and find that the final size of the infected people is 25,717, which agrees nearly with the real weekly reported case data 25,400 from November 1, 2015 to April 10, 2016 in Rio de Janeiro, Brazil. Highlights • A Zika virus (ZIKV) model with spatial heterogeneity is developed. • The threshold dynamics of the ZIKV model are given. • The spatial distribution and final size of the ZIKV are strongly dependent on the location when ZIKV appears in a region. • It is useful to understand the influences of spatial heterogeneity on the dynamics of ZIKV. [ABSTRACT FROM AUTHOR]