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The lifespan of core graphite under neutron irradiation in a commercial molten salt reactor (MSR) has an important influence on its economy. Flattening the fast neutron flux (≥0.05 MeV) distribution in the core is the main method to extend the graphite irradiation lifespan. In this paper, the effects of the key parameters of MSRs on fast neutron flux distribution, including volume fraction (VF) of fuel salt, pitch of hexagonal fuel assembly, core zoning, and layout of control rod assemblies, were studied. The fast neutron flux distribution in a regular hexagon fuel assembly was first analyzed by varying VF and pitch. It was demonstrated that changing VF is more effective in reducing the fast neutron flux in both global and local graphite blocks. Flattening the fast neutron flux distribution of a commercial MSR core was then carried out by zoning the core into two regions under different VFs. Considering both the fast neutron flux distribution and burnup depth, an optimized core was obtained. The fast neutron flux distribution of the optimized core was further flattened by the rational arrangement of control rod channels. The calculation results show that the final optimized core could reduce the maximum fast neutron flux of the graphite blocks by about 30% and result in a more negative temperature reactivity coefficient, while slightly decreasing the burnup and maintaining a fully acceptable core temperature distribution.

Abstract Background Influenza A viruses have undergone rapid evolution with virulent; however, complete and comprehensive data on gene evolution and amino acid variation of HA and NA in immunosuppressed patients was few. In this study, we analysed molecular epidemiology and evolution of influenza A viruses in immunosuppressed population, and immunocompetent population were used as controls. Methods Full sequences of HA and NA of A(H1N1)pdm09 and A(H3N2) were acquired through reverse transcription-polymerase chain reaction (RT-PCR). HA and NA genes were sequenced using the Sanger method and phylogenetically analysed using ClustalW 2.10 and MEGA software version 11.0. Results During the 2018–2020 influenza seasons, 54 immunosuppressed and 46 immunocompetent inpatients screened positive for influenza A viruses by using the quantitative real-time PCR (qRT-PCR) were enrolled. 27 immunosuppressed and 23 immunocompetent nasal swab or bronchoalveolar lavage fluid samples were randomly selected and sequenced using the Sanger method. A(H1N1)pdm09 were detected in 15 samples and the remaining 35 samples were A(H3N2) positive. By analyzing the HA and NA gene sequences of these virus strains, we found that all A(H1N1)pdm09 viruses shared high similarities to each other and the HA and NA genes of these viruses exclusively belonged to subclade 6B.1A.1. Some NA genes of A(H3N2) viruses were not in the same clade as those of A/Singapore/INFIMH-16-0019/2016 and A/Kansas/14/2017, which may have led to A(H3N2) being the dominant strain in the 2019–2020 influenza season. Both A(H1N1)pdm09 and A(H3N2) viruses showed similar evolutionary lineages patterns of HA and NA between immunosuppressed and immunocompetent patients. Compared with the vaccine strains, there were no statistically significant of HA and NA genes and amino acid sequences of influenza A viruses in immunosuppressed and immunocompetent patients. However, the oseltamivir resistance substitution of NA-H275Y and R292K have been observed in immunosuppressed patients. Conclusions A(H1N1)pdm09 and A(H3N2) viruses showed similar evolutionary lineages patterns of HA and NA between immunosuppressed and immunocompetent patients. Both immunocompetent and immunosuppressed patients have some key substitutions, which should be of note monitored, especially those with potential to affect the viral antigen.

Abstract Introduction Bleb scarring is the most important complication of trabeculectomy. Changing the application position of mitomycin C (MMC) during trabeculectomy might affect the surgery outcome. Our aim is to compare the effectiveness and safety of intraocular pressure (IOP) lowering in two different application sites of mitomycin in trabeculectomy. Methods This retrospective trial compared the surgical outcomes of 177 eyes that underwent trabeculectomy with adjunctive mitomycin C. In 70 eyes, an MMC-soaked sponge was applied under the scleral flap without touching Tenon’s capsule. In 107 eyes, an MMC-soaked sponge was applied under the scleral flap covered by Tenon’s capsule. Outcome measures were the IOP, best-corrected visual acuity (BCVA), success rates, and incidence of complications. Results Within both groups, a highly significant IOP reduction was seen during follow-up. The effectiveness in reducing IOP and the change in best-corrected visual acuity (BCVA) were similar between the two groups. Thin-walled blebs and postoperative hypotony were seen more often when MMC-soaked sponges were applied under the scleral flap covered by Tenon’s capsule (P = 0.008 and P = 0.012, respectively). There was no significant difference in BCVA or other complications in either group. Conclusion Since the effectiveness of IOP reduction was similar between both groups and with a low incidence of thin-walled blebs and hypotony, the subscleral application without touching Tenon’s capsule seems to be the safer application site of MMC during trabeculectomy.

The SM-MSR (small modular molten salt reactor) has a good prospect for development with regards to combining the superiority of the molten salt reactor and modularization technologies, showing the advantages of safety, reliability, low economic cost and flexibility of site selection. However, because its internal structural parts are not easily replaced, and the outer shielding structure is limited, the lifespan of the reactor vessel and its in-reactor shielding design needs to be addressed. In order to find an optimal shielding model with both high fuel efficiency and strong radiation shielding capability, five different design schemes were proposed in this work, which varied in thickness and boron concentration in inner-shielding materials. The neutron/gamma flux and DPA (displacements per atom)/helium production rates were evaluated to obtain an appropriate scheme. Several beneficial results were obtained. Considering the above factors and the actual manufacturing process, 20 cm-thick boron graphite with a 5 wt% Boron-10 concentration combined with a 1 cm-thick Hastelloy barrel was chosen as the in-reactor shielding structure. Outside the reactor, the neutron flux was reduced to 8.33 × 1010 cm−2 s−1, and the gamma flux was decreased to 1.13 × 1011 cm−2 s−1. The vessel/barrel material could maintain a lifespan of more than 10 years, while the burnup depth was 6.25% lower than that of a model without inner-shielding. The conclusions of this research can provide important references for the shielding design and parameter selections of small molten salt reactors in the future.

Objective: The present study aimed to explore the feasibility and safety of robot-assisted total hysterectomy by transvaginal natural orifice transluminal endoscopic surgery (vNOTES). Methods: In this study, the clinical data of 37 patients who underwent da Vinci robot-assisted total hysterectomy by vNOTES between September 1, 2019 and March 31, 2022 at the Department of Gynecology, the First Affiliated Hospital of Zhengzhou University, China were retrospectively analyzed. Clinical characteristics, operative postoperative complications, surgical outcomes, and postoperative pain scores were collected and analyzed. Results: The average age of the patients included in the study was 47.43 ± 4.44 years. The body mass index (BMI) was calculated using the formula BMI = body weight (kg)/height2 (m2). The average BMI was 23.16 ± 2.72 kg/m2. Among the 37 patients, 30 patients underwent total hysterectomy and bilateral salpingectomy, of which 11 patients underwent ovarian cystectomy simultaneously. Among these 11 patients, three had bilateral ovarian cysts and eight had unilateral ovarian cysts, with the largest cyst diameter measuring 8 cm. The remaining seven patients underwent total hysterectomy and bilateral salpingo-oophorectomy. The average operative time was 86.19 ± 17.83 min, and the estimated intraoperative blood loss was 24.46 ± 15.40 mL, with no intraoperative complications reported. The time to the first postoperative exhaust was 18.51 ± 6.63 h, and the average postoperative length of hospital stay was 3.81 ± 1.05 days. The postoperative visual analog scale (VAS) pain scores were 5.30 ± 0.91 at 24 h after surgery, 3.30 ± 0.70 at 36 h after surgery, and 1.14 ± 0.92 at 48 h after surgery. Only one patient experienced a fever exceeding 38.5 °C, which resolved after receiving antibiotic treatment. Conclusion: The use of the da Vinci robot-assisted total hysterectomy by vNOTES demonstrated safety and offers several advantages. These include reduced surgical trauma, an aesthetic incision, decreased pain, and shorter duration of postoperative exhaust time and hospital stay. These benefits contribute to accelerated postoperative rehabilitation.

Abstract Background Compared with immunocompetent patients, immunosuppressed patients have higher morbidity and mortality, a longer duration of viral shedding, more frequent complications, and more antiviral resistance during influenza infections. However, few data on this population in China have been reported. We analysed the clinical characteristics, effects of antiviral therapy, and risk factors for admission to the intensive care unit (ICU) and death in this population after influenza infections and explored the influenza vaccination situation for this population. Methods We analysed 111 immunosuppressed inpatients who were infected with influenza virus during the 2015–2020 influenza seasons. Medical data were collected through the electronic medical record system and analysed. Univariate analysis and multivariate logistics analysis were used to identify risk factors. Results The most common cause of immunosuppression was malignancies being treated with chemotherapy (64.0%, 71/111), followed by haematopoietic stem cell transplantation (HSCT) (23.4%, 26/111). The most common presenting symptoms were fever and cough. Dyspnoea, gastrointestinal symptoms and altered mental status were more common in HSCT patients than in patients with immunosuppression due to other causes. Approximately 14.4% (16/111) of patients were admitted to the ICU, and 9.9% (11/111) of patients died. Combined and double doses of neuraminidase inhibitors did not significantly reduce the risk of admission to the ICU or death. Risk factors for admission to the ICU were dyspnoea, coinfection with other pathogens and no antiviral treatment within 48 h. The presence of dyspnoea and altered mental status were independently associated with death. Only 2.7% (3/111) of patients less than 12 months old had received a seasonal influenza vaccine. Conclusion Fever and other classic symptoms of influenza may be absent in immunosuppressed recipients, especially in HSCT patients. Conducting influenza virus detection at the first presentation seems to be a good choice for early diagnosis. Clinicians should pay extra attention to immunosuppressed patients with dyspnoea, altered mental status, coinfection with other pathogens and no antiviral treatment within 48 h because these patients have a high risk of severe illness. Inactivated influenza vaccines are recommended for immunosuppressed patients.

X-linked juvenile retinoschisis (XLRS), caused by the mutation of RS1 gene, is one of the most common causes of macular degeneration for male adolescents. The mutations and clinical manifestations of the disease are diverse. Neither the relationship between the genotypes and phenotypes, nor the radical treatment like gene therapy has been found by now. Retrospective studies have shown that carbonic anhydrase inhibitors can help reduce cysts. However, the specifically pharmacological mechanism remains unknown. Here, we culture induced pluripotent stem cells by drawing peripheral blood from a patient with XLRS, which are supposed to facilitate related researches.

Small modular reactors with power below 300 MW have the advantages of small specific mass, long lifetime, and flexible power supply, and they are suitable for providing power support for small and medium-sized towns with small populations and remote areas without grid coverage. In this paper, a small modular S-CO2-cooled molten salt reactor is proposed, and the design of a 10 MW small modular chlorine salt fast reactor (sm-MCFR) with 20 years of operation without refueling is presented. The neutron feasibility of the S-CO2-cooled small modular chlorine fast reactor is analyzed in terms of neutron energy spectrum, reactivity control, temperature reactivity coefficient, and power distribution. A distinctive feature of the sm-MCFR is the use of chlorine salts with high heavy metal solubility and a hard energy spectrum, allowing the core size to be minimized while maintaining the maximum lifetime. The designed core is about 2.44 m in diameter and 2.24 m in height. Meanwhile, the sm-MCFR uses control drum control as the control system, which can effectively achieve reactivity control without increasing the reactor size. The final optimized sm-MCFR has a negative temperature reactivity coefficient, which is necessary to ensure the safe operation of the reactor.

Abstract Background Influenza A(H1N1)pdm09 viruses have undergone rapid evolution, and in recent years the complementary and antagonistic effects of HA and NA have gathered more attentions; however, the effects of co-occurring mutations in HA and NA on the patients’ clinical characteristics are still poorly understood. In this study, we analyzed molecular epidemiology and evolution of A(H1N1) pdm09, explored co-occurring mutations of HA and NA, and investigated effect of co-occurring mutations on patients’ clinical features. Methods A(H1N1)pdm09 was confirmed by reverse transcription-polymerase chain reaction. HA and NA genes were sequenced and phylogenetically analyzed. Clinical characteristics of the co-occurring mutations were analyzed statistically. Results By analyzing the HA and NA gene sequences of 33 A(H1N1)pdm09 viruses during the 2015–2017 influenza season, we found that all the viruses shared high similarities to each other and the HA genes of these viruses exclusively belonged to subclade 6B.1A. Several unreported substitutions in HA and NA proteins were observed, furthermore, co-occurring mutations of HA-V169T, A278S, E508G, D518E and NA-V67I were detected in 30.3% (10/33) A(H1N1)pdm09 virus strains when comparing with vaccine strains A/California/07/2009 and A/Michigan/45/2015 (H1N1). Sore throat was significantly associated with co-occurring mutations in HA and NA of A(H1N1)pdm09 (χ2, P

X-linked juvenile retinoschisis (XLRS) is an inherited disease characterized by splitting within inner retinal layers and impaired vision, which begins in childhood and occurs mostly in males. Peripheral blood mononuclear cells (PBMCs) were isolated from a seven-year-old boy carrying a hemizygous mutation in RS1 gene, and were reprogrammed into human induced pluripotent stem cells (iPSCs) using non-integrative episomal vectors. The cell line, ZOCi003-A, had normal karyotype, expressed pluripotency markers, and could differentiate into three germ layers in vivo. This IPSC line may be used for studying the molecular basis of XLRS and selecting potential therapeutic targets and drugs.

Background and Objectives: Choroidal neovascularization (CNV) is a common pathologic lesion that occurs in various chorioretinopathy, but very limited published data have reported in pediatric patients. This study aimed to investigate the etiologic factors, clinical features, and treatment outcomes of choroidal neovascularization (CNV) in children.Methods: In this study, 33 eyes in 30 patients aged 18 years or younger with CNV were included. Comprehensive ophthalmic examination was performed in all the patients. The demographic profiles, laterality, visual acuity, optical coherence tomographic findings, fundus fluorescein angiographic findings, and the underlying pathology were analyzed. The types, locations, treatment outcomes, and recurrences of CNV were noted.Results: The average age was 11.2 ± 4.6 (range, 1–18) years. Most CNVs affecting children were classic and type 2. The most common etiologic factors of CNV in pediatric patients were congenital/developing abnormalities (9/30, 30.0%) and inflammatory retinochoroidopathy (9/30, 30.0%), followed by idiopathic CNV (8/30, 26.7%). Subtype analysis showed that the etiologic factor was inflammatory retinochoroidopathy in children 12 years or older, whereas congenital/developing abnormalities were present in children younger than 12 years. Eyes with active CNVs required a mean of 1.40 ± 0.58 injections. No recurrence was observed during follow-up.Conclusions: The etiologic factors of CNV in young Chinese patients were diverse, with congenital/developing abnormalities, inflammatory retinochoroidopathy and idiopathic CNV being the 3 most common ones. Eyes with active CNVs had good responses to antivascular endothelial growth factor treatment with low recurrence.

Abstract Background Respiratory variations in the inferior vena cava diameter (ΔIVCD) have been studied extensively with respect to their value in predicting fluid responsiveness, but the results are conflicting. The aim of this meta-analysis was to explore the value of ΔIVCD for predicting fluid responsiveness in patients with circulatory shock receiving mechanical ventilation. Methods PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched up to June 2017. The diagnostic OR (DOR), sensitivity, and specificity were calculated. The summary ROC curve was estimated, and the area under the ROC curve (AUROC) was calculated. Results Overall, 603 patients were included in this review, 324 (53.7%) of whom were fluid-responsive. The cutoff values of ΔIVCD varied across studies, ranging from 8% to 21%. Heterogeneity between studies was assessed with an overall Q = 0.069, I 2 = 0%, and P = 0.483. The pooled sensitivity and specificity for the overall population were 0.69 (95% CI, 0.51–0.83) and 0.80 (95% CI, 0.66–0.89), respectively. The DOR was 9.28 (95% CI, 2.33–36.98). AUROCs were reported in five studies. Overall, the pooled AUROC was 0.82 (95% CI, 0.79–0.85). Conclusions The findings of this study suggest that the ΔIVCD performed moderately well in predicting fluid responsiveness in patients with circulatory shock receiving mechanical ventilation.

AtNHX5 and AtNHX6, the endosomal Na+,K+/H+ antiporters in Arabidopsis, play an important role in plant growth and development. However, their function in K+ and pH homeostasis remains unclear. In this report, we characterized the function of AtNHX5 and AtNHX6 in K+ and H+ homeostasis in Arabidopsis. Using a yeast expression system, we found that AtNHX5 and AtNHX6 recovered tolerance to high K+ or salt. We further found that AtNHX5 and AtNHX6 functioned at high K+ at acidic pH while AtCHXs at low K+ under alkaline conditions. In addition, we showed that the nhx5 nhx6 double mutant contained less K+ and was sensitive to low K+ treatment. Overexpression of AtNHX5 or AtNHX6 gene in nhx5 nhx6 recovered root growth to the wild-type level. Three conserved acidic residues, D164, E188, and D193 in AtNHX5 and D165, E189, and D194 in AtNHX6, were essential for K+ homeostasis and plant growth. nhx5 nhx6 had a reduced vacuolar and cellular pH as measured with the fluorescent pH indicator BCECF or semimicroelectrode. We further show that AtNHX5 and AtNHX6 are localized to Golgi and TGN. Taken together, AtNHX5 and AtNHX6 play an important role in K+ and pH homeostasis in Arabidopsis. Three conserved acidic residues are essential for K+ transport.

The present paper systematically investigated pore scale thermal hydraulics characteristics of molten salt cooled high temperature pebble bed reactor. By using computational fluid dynamics (CFD) methods and employing simplified body center cubic (BCC) and face center cubic (FCC) model, pressure drop and local mean Nusselt number are calculated. The simulation result shows that the high Prandtl number molten salt in packed bed has unique fluid-dynamics and thermodynamic properties. There are divergences between CFD results and empirical correlations’ predictions of pressure drop and local Nusselt numbers. Local pebble surface temperature distributions in several default conditions are investigated. Thermal removal capacities of molten salt are confirmed in the case of nominal condition; the pebble surface temperature under the condition of local power distortion shows the tolerance of pebble in extreme neutron dose exposure. The numerical experiments of local pebble insufficient cooling indicate that in the molten salt cooled pebble bed reactor, the pebble surface temperature is not very sensitive to loss of partial coolant. The methods and results of this paper would be useful for optimum designs and safety analysis of molten salt cooled pebble bed reactors.

BACKGROUND: Since May 2009, exposure of the population of Beijing, China to pH1N1 has resulted in an increase in respiratory illnesses. Limited information is available on the etiology and clinical characteristics of the influenza-like illness (ILI) that ensued in adults following the pH1N1 pandemic. METHODS: Clinical and epidemiological data of ILI in adults was collected. A total of 279 throat swabs were tested for twelve respiratory viruses using multiplex RT-PCR. Clinical characteristics of influenza A in outpatients versus test-negative patients were compared using Pearson's χ2 and the Mann-Whitney U test. 190 swabs were tested for pH1N1 by virus isolation. Consultation rates for ILI were compared between 2009 and 2010. RESULTS: One or two virus were detected in 29% of the samples. Influenza A virus (FLU-A) accounted for 22.9% (64/279). Other viruses were present at a frequency less than 3.0%. Cough was significantly associated with Influenza A virus infection (χ2, p