Search

The development of space vehicle guidance and control systems gradually becomes a focus in recent research as a key to space vehicles’ information processing and control in the space environment. In general, among the popular methods in G&C systems, artificial intelligence-based algorithms contain a wide prospect. This study offers descriptions of the current methods in AI-based algorithms, proposed challenges involved in this field, and described the recent achievements in solving these issues. To be specific, the basic descriptions of the controlling systems as well as the various state-of-art machine learning approaches that are suitable for the G&C system are demonstrated and analyzed including ANN, DNN, RL, SVM, DRL, etc. According to the analysis, the challenges as well as the drawbacks of the advanced scenarios are estimated as well as propose the future prospects to improve the performance of landing. Overall, these results shed light on guiding further exploration of aerospace vehicles.

As a key indicator to measure the mental health status, psychological security level of Chinese college students and its changes over time are of great value to examine.A cross-temporal meta-analysis was performed using papers that measured the psychological security level of Chinese college students using the Security Questionnaire between 2006 and 2019. In addition, a time lag analysis was conducted to define whether the selected macro social indicators can explain the changes in the psychological security level.A total of 58 papers involving 28,352 Chinese college students were included in the final sample. The results revealed that scores of psychological security and its two factors were significantly negatively correlated with the year. Scores of psychological security and its two factors were significantly associated with five social indicators of economic condition (residents' consumption level), social connectedness (divorce rate, urbanization level) and overall threat (college enrollment rate, crime rate), suggesting that social change may account for the decline in psychological security level of Chinese college students.The underlying mechanism is only discussed at a theoretical level. Thus, future studies can collect the relating empirical evidence to test the proposed theoretical model.Our study revealed a decreasing trend of Chinese college students' psychological security level across time, which was associated with macro-social changes in diverse areas. In addition, combined with the corresponding macro-social indicators, a three-dimensional theoretical framework is proposed to explain the psychological security for college students as a group.

To investigate the impact of early versus delayed surgery on sensory abnormalities in acute traumatic central cord syndrome (ATCCS).Pressure pain threshold (PPT), temporal summation (TS), conditioned pain modulation (CPM) and pain assessments were performed in 72 ATCCS patients (early vs. delayed surgical treatment: 32 vs. 40) and 72 healthy subjects in this ambispective cohort study. These examinations, along with mechanical detection threshold (MDT) and disabilities of arm, shoulder and hand (DASH), were assessed at 2 years postoperatively.Preoperatively, more delayed surgical patients had neuropathic pain below level compared with early surgical patients (P 0.05). Both early and delayed surgical patients showed reduced PPT in common painful areas and increased TS, while reduced CPM only existed in the latter (P 0.05). Reduced PPT in all tested areas, along with abnormalities in TS and CPM, was observed in patients with durations over 3 months. Both incidences and intensities of pain and pain sensitivities in common painful areas were reduced in both treatment groups postoperatively, but only early surgical treatment improved the CPM and TS. Follow-up analysis demonstrated a higher MDT and lower PPT in hand, greater TS, greater DASH, lower pain intensities and higher incidence of dissatisfaction involving sensory symptoms in delayed surgical patients than in early surgical patients (P 0.05).Central hypersensitivity may be involved in the persistence of sensory symptoms in ATCCS, and this augmented central processing may commence in the early stage. Early surgical treatment may reverse dysfunction of endogenous pain modulation, thus reducing the risk of central sensitization and alleviating sensory symptoms.

Observational epidemiology studies suggested a relationship between the gut microbiome and primary liver cancer. However, the causal relationship remains unclear because of confounding factors and reverse causality. We aimed to explore the causal role of the gut microbiome in the development of primary liver cancer, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC).Mendelian randomization (MR) study was conducted using summary statistics from genome-wide association studies (GWAS) of the gut microbiome and liver cancer, and sequencing data from a case-control study validated the findings. A 5-cohort GWAS study in Germany (N = 8956) served as exposure, whilst the UK biobank GWAS study (N = 456 348) served as an outcome. The case-control study was conducted at the First Affiliated Hospital of Wenzhou Medical University from December 2018 to October 2020 and included 184 HCC patients, 63 ICC patients and 40 healthy controls.A total of 57 features were available for MR analysis, and protective causal associations were identified for Family_Ruminococcaceae (OR = 0.46 [95% CI, 0.26-0.82]; p = .009) and Genus_Porphyromonadaceae (OR = 0.59 [95% CI, 0.42-0.83]; p = .003) with HCC, and for Family_Porphyromonadaceae (OR = 0.36 [95% CI, 0.14-0.94]; p = .036) and Genus_Bacteroidetes (OR = 0.55 [95% CI, 0.34-0.90]; p = .017) with ICC respectively. The case-control study results showed that the healthy controls had a higher relative abundance of Family_Ruminococcaceae (p = .00033), Family_Porphyromonadaceae (p = .0055) and Genus_Bacteroidetes (p = .021) than the liver cancer patients.This study demonstrates that Ruminococcaceae, Porphyromonadaceae and Bacteroidetes are related to a reduced risk of liver cancer (HCC or ICC), suggesting potential significance for the prevention and control of liver cancer.

To investigate the presence of altered central pain processing in patients with failed back surgery syndrome (FBSS) using quantitative sensory testing (QST).This study included 34 patients with FBSS, 102 patients post-lumbar surgery without low back pain (LBP), and 102 healthy subjects. All subjects underwent both pressure pain threshold (PPT) and conditioned pain modulation (CPM) in both local and remote pain-free areas, as well as temporal summation (TS) in a remote pain-free area. All patient subjects were assessed using the Pain Catastrophizing Scale (PCS), Beck Anxiety Inventory (BAI), Beck Depression Index (BDI), Numeric rating pain scale (NRS) and Oswestry Disability Index (ODI).Compared with both control groups, FBSS patients showed a reduction in both PPT and CPM in both tested areas, along with increased TS in a pain-free area (P 0.05). Furthermore, the patients with FBSS had a significantly higher prevalence of anxiety, depression and pain catastrophizing thoughts than the patient controls (P 0.05). In the FBSS patients, there was a significant correlation between LBP at rest and both CPM and TS in the pain-free areas, and QST measurements were also associated with the ODI, PCS and BAI (P 0.05).These findings support the existence of augmented central pain processing in patients with FBSS, which may be caused by dysfunction of endogenous pain facilitation and inhibition. This central amplification of pain may contribute to both LBP intensity and disability in FBSS patients. Therefore, treatment efforts should take into account functional alterations in the central nervous system of FBSS patients.

In recent years, the clean and environmentally-friendly renewable energy technologies have developed rapidly. How to ensure balance and flexible output of power system has become a new challenge after all kinds of volatile power sources are connected to the power system. Among different forms of stored energy, gravity energy storage, as a kind of physical energy storage with competitive environmental protection and economy, has received wide attention for its advantages such as high safety, high cost-performance, great environmental-friendliness and strong environmentally adaptation. This paper firstly introduces the basic principles of gravity energy storage, classifies and summarizes dry-gravity and wet-gravity energy storage while analyzing the technical routes of different types of gravity energy storage. Separated into groups of dry and wet gravity energy storage, these storage shows similar features and promising advantages in both environmental and economical way. Among them, LEM-GES shows a new concept of storage and will be the target for future study. Then follows an analysis of the practical applications of gravity energy storage in real scenarios such as mountains, wind farms, oceans, energy depots and abandoned mines, and finally an outlook on the future development trends of gravity energy storage technology.

Unlike conventional monolithic hydrogels with covalent cross-linkage that are typically elastic, colloidal gels assembled by reversibly assembled particles as building blocks have shown fascinating viscoelastic properties. They follow a gel-sol transition upon yielding and recover to the initial state upon the release of the shear force (so-called shear-thinning and self-healing behavior); this makes them an ideal candidate as injectable and moldable biomaterials for tissue regeneration. The immune response provoked by the implantation of the colloidal gels with special viscoelastic and structural features is critical for the successful integration of the implants with the host tissues, which, however, remains little explored. Since macrophages are known as the primary immune cells in determining the inflammatory response against the implants, we herein investigated in vitro macrophage polarization and in vivo inflammatory response induced by gelatin-based colloidal gels as compared to monolithic gels. Specifically, self-healing colloidal gels composed of pure gelatin nanoparticles, or methacrylate gelatin (GelMA) nanoparticles to allow secondary covalent cross-linkage were compared with GelMA bulk hydrogels. We demonstrated that hydrogel's elasticity plays a more dominant role rather than the structural feature in determining in vitro macrophage polarization evidenced by the stiffer gels inducing pro-inflammation M2 macrophage phenotype as compared to soft gels. However, subcutaneous implantation revealed a significantly alleviated immune response characterized by less fibrous capsule formation for the colloidal gels as compared to bulk gels of similar matrix elasticity. We speculated this can be related to the improved permeability of the colloidal gels for cell penetration, thereby leading to less fibrosis. In general, this study provided in-depth insight into the biophysical regulator of hydrogel materials on macrophage behavior and related inflammatory response, which can further direct future implant design and predict biomaterial–host interactions for immunotherapy and regenerative medicine. IMPACT STATEMENT: Macrophages response to implanted biomaterials is a highly regulated process that influences device functionality and clinical outcome. Nowadays, the viscoelastic properties of colloidal versus monolithic hydrogels on macrophage phenotype in vitro and the host inflammatory response are not known. Our study found that colloidal hydrogels composed of nanoparticles of gelatin and methacrylate gelatin (GelMA) led to more anti-inflammatory polarization especially on soft colloidal gel (5.9 KPa) compared to bulk GelMA hydrogels. It suggested that macrophage response can be mechanically regulated by the viscoelastic signals of the hydrogels, which could be a promising strategy for the future design and application of novel biomaterials.

Purpose Imaging the PARP expression using 18F probes has been approved in clinical trials. Nevertheless, hepatobiliary clearance of both 18F probes hindered their application in monitoring abdominal lesions. Our novel 68Ga-labelled probes aim for fewer abdominal signals while ensuring PARP targeting by optimizing the pharmacokinetic properties of radioactive probes. Methods Three radioactive probes targeted PARP were designed, synthesized, and evaluated based on the PARP inhibitor Olaparib. These 68Ga-labelled radiotracers were assessed in vitro and in vivo. Results Precursors that did not lose binding affinity for PARP were designed, synthesized, and then labelled with 68Ga in high radiochemical purity (> 97%). The 68Ga-labelled radiotracers were stable. Due to the increased expression of PARP-1 in SK-OV-3 cells, the uptake of the three radiotracers by SK-OV-3 cells was significantly greater than that by A549 cells. PET/CT imaging of the SK-OV-3 models indicated that the tumor uptake of 68Ga-DOTA-Olaparib (0.5 h: 2.83 ± 0.55%ID/g; 1 h: 2.37 ± 0.64%ID/g) was significantly higher than that of the other 68Ga-labelled radiotracers. There was a significant difference in the T/M (tumor-to-muscle) ratios between the unblocked and blocked groups as calculated from the PET/CT images (4.07 ± 1.01 vs. 1.79 ± 0.45, P = 0.0238 Conclusion As the first 68Ga-labelled PARP inhibitor, 68Ga-DOTA-Olaparib displayed high stability and quick PARP imaging in a tumor model. This compound is thus a promising imaging agent that can be used in a personalized PARP inhibitor treatment regimen.

Liver cancer is an aggressive tumor originating in the liver with a dismal prognosis. Current evidence suggests that liver cancer is the fifth most prevalent cancer worldwide and the second most deadly type of malignancy. Tumor heterogeneity accounts for the differences in drug responses among patients, emphasizing the importance of precision medicine. Patient-derived models of cancer are widely used preclinical models to study precision medicine since they preserve tumor heterogeneity ex vivo in the study of many cancers. Patient-derived models preserving cell-cell and cell-matrix interactions better recapitulate in vivo conditions, including patient-derived xenografts (PDXs), induced pluripotent stem cells (iPSCs), precision-cut liver slices (PCLSs), patient-derived organoids (PDOs), and patient-derived tumor spheroids (PDTSs). In this review, we provide a comprehensive overview of the different modalities used to establish preclinical models for precision medicine in liver cancer.

A novel adaptive method to achieve both path following and formation moving along desired orbits in the presence of a spatio-temporal flowfield is presented. The flowfield is a spatio-temporal general flow with unknown time-varying parameters. The so-called \emph{congelation of variables} method is used to estimate the time-varying flow parameters, which do not have any restrictions on the rate of their variation. The asymptotic properties of the resulting adaptive system are studied in detail. Simulation results demonstrate the effectiveness of the proposed method.

Background Literature review have shown that sarcopenia substantially alters the postoperative outcomes after liver resection for malignant tumors. However, these retrospective studies do not distinguish cirrhotic and non-cirrhotic liver cancer patients, nor combine the assessment of muscle strength in addition to muscle mass. The purpose of this study is to study the relationship between sarcopenia and short-term outcomes after hepatectomy in patients with non-cirrhotic liver cancer. Methods From December 2020 to October 2021, 431 consecutive inpatients were prospectively enrolled in this study. Muscle strength and mass were assessed by handgrip strength and the skeletal muscle index (SMI) on preoperative computed tomographic scans, respectively. Based on the SMI and the handgrip strength, patients were divided into four groups: group A (low muscle mass and strength), group B (low muscle mass and normal muscle strength), group C (low muscle strength and normal muscle mass), and group D (normal muscle mass and strength). The main outcome was major complications and the secondary outcome was 90-d Readmission rate. Results After strictly exclusion, 171 non-cirrhosis patients (median age, 59.00 [IQR, 50.00–67.00] years; 72 females [42.1%]) were selected in the final analysis. Patients in group A had a statistically significantly higher incidence of major postoperative complications (Clavien–Dindo classification ≥ III) (26.1%, p = 0.032), blood transfusion rate (65.2%, p p = 0.037) and hospitalization expenses (60,842.00 [IQR, 35,563.10–87,575.30], p p = 0.025) and open approach (hazard ratio, 2.56; 95% CI, 1.01–6.49; p = 0.004) were independent risk factors associated with major postoperative complications. Conclusions Sarcopenia is closely related to poor short-term postoperative outcomes in non-cirrhosis liver cancer patients and the assessment that combines muscle strength and muscle mass can simply and comprehensively identify it. Trial registration ClinicalTrials.gov identifiers NCT04637048. (19/11/2020).

BackgroundSarcopenia has a remarkable negative impact on patients with liver diseases. We aimed to evaluate the impact of preoperative sarcopenia on the short-term outcomes after hepatectomy in patients with benign liver diseases.MethodsA total of 558 patients with benign liver diseases undergoing hepatectomy were prospectively reviewed. Both the muscle mass and strength were measured to define sarcopenia. Postoperative outcomes including complications, major complications and comprehensive complication index (CCI) were compared among four subgroups classified by muscle mass and strength. Predictors of complications, major complications and high CCI were identified by univariate and multivariate logistic regression analysis. Nomograms based on predictors were constructed and calibration cures were performed to verify the performance.Results120 patients were involved for analysis after exclusion. 33 patients were men (27.5%) and the median age was 54.0 years. The median grip strength was 26.5 kg and the median skeletal muscle index (SMI) was 44.4 cm2/m2. Forty-six patients (38.3%) had complications, 19 patients (15.8%) had major complications and 27 patients (22.5%) had a CCI ≥ 26.2. Age (p = 0.005), SMI (p = 0.005), grip strength (p = 0.018), surgical approach (p = 0.036), and operation time (p = 0.049) were predictors of overall complications. Child-Pugh score (p = 0.037), grip strength (p = 0.004) and surgical approach (p = 0.006) were predictors of major complications. SMI (p = 0.047), grip strength (p p = 0.014) were predictors of high CCI. Among the four subgroups, patients with reduced muscle mass and strength showed the worst short-term outcomes. The nomograms for complications and major complications were validated by calibration curves and showed satisfactory performance.ConclusionSarcopenia has an adverse impact on the short-term outcomes after hepatectomy in patients with benign liver diseases and valuable sarcopenia-based nomograms were constructed to predict postoperative complications and major complications.

Background Common ankle sprains are often accompanied by injury to the subtalar joint, which eventually leads to subtalar joint instability. Because the clinical manifestations for subtalar joint instability are similar to ankle joint injuries, these are often overlooked. This study aimed to establish an animal model of subtalar joint instability to study post-traumatic osteoarthritis of the subtalar joint caused by long-term subtalar joint instability and to provide a reference for future clinical research on chronic subtalar joint instability. Methods In all, 24 C57BL/6 male mice were randomly divided into three groups: Sham, cervical ligament (CL) transection and CL + calcaneofibular ligament (CFL) transection groups. One week after surgical operation, all mice were trained to run in the mouse rotation fatigue machine every day. During this period, a balance beam test was used to evaluate the motor level and coordination ability of the mice before the operation and three days, one week, four weeks, eight weeks, and twelve weeks after operation. Further, post-traumatic osteoarthritis of the subtalar joint was quantified via micro-CT and histological staining. Results The mice in the partial ligament transection group took significantly longer than those in the Sham group to pass through the balance beam and showed an increased number of hindfoot slips. Micro-CT analysis showed that the subtalar bone volume fraction in the CL + CFL transection group and CL transection group was 5.8% and 2.8% higher than that in the Sham group, respectively. Histological staining showed obvious signs of post-traumatic osteoarthritis (PTOA) in the subtalar joint of the ligament transection group. Conclusions The transection of CL and CL + CFL can cause instability of the subtalar joint in mice, resulting in a decrease in motor coordination, and long-term instability of the subtalar joint in mice can cause PTOA of the subtalar joint, which is manifested as destruction and loss of articular cartilage.

Background Cytomegalovirus (CMV) disease is associated with increased morbidity and mortality following solid organ and hematopoietic cell transplantation. Currently, standard of care CMV treatments often have significant myelosuppressive or renal toxicities. Given letermovir’s favorable safety profile when used prophylactically, it may be a safe and efficacious alternative agent for CMV treatment. Methods A proof-of-concept, open-label trial was conducted in patients who lacked effective therapeutic options or presented with baseline organ dysfunction. Participants were eligible for enrollment if they were ≥12 years old and had documented CMV infection refractory to treatment defined as failure to achieve >1 log reduction in CMV viral load (VL) (when VL > 500 IU/mL) or lack of clinical improvement for CMV end-organ disease after ≥14 days of standard CMV treatment. Alternatively, patients with severe myelosuppression and renal dysfunction at baseline or genotypic antiviral resistance were also eligible. Participants were excluded if their current CMV infection developed while receiving letermovir for CMV prophylaxis. Letermovir was administered daily (480 mg PO/IV) for up to 12 weeks, with optional additional 12 weeks of treatment for secondary prophylaxis if clinically indicated. Results Ten patients met eligibility criteria and were enrolled. Reasons for enrollment included ganciclovir resistance (1/10), refractory CMV infection (6/10), renal dysfunction (7/10), and myelosuppression (7/10). The median baseline CMV VL was 1272 IU/ml [interquartile range (IQR); 925, 2546]. Six patients completed the study, three died due to complications of primary disease, and one discontinued due to diarrhea. Five patients (50%) had documented CMV viremia clearance, with a median time to first unquantifiable/undetectable CMV VL of 13 days [IQR; 9,18] and a median treatment duration of 53 days [IQR; 15,84]. Infections and GI disorders were the most common adverse events (AE), none considered related to study drug. No unexpected AE were observed during letermovir treatment. Conclusion Letermovir may be a safe and tolerable alternative for patients with treatment refractory CMV infection or for patients with severe baseline myelosuppression and renal dysfunction. Disclosures Matthew Cheng, MD, AstraZeneca: Honoraria|Cidara Therapeutics: Grant/Research Support|Scynexis Inc.: Grant/Research Support Sandra Burchett, MD, MSc, merck: Grant/Research Support Sarah P. Hammond, MD, F2G: Advisor/Consultant|F2G: Grant/Research Support|GSK: Grant/Research Support|Merck: Grant/Research Support|pfizer: Advisor/Consultant|Scynexis: Grant/Research Support Nicolas C. Issa, MD, AiCuris: Grant/Research Support|Merck: Grant/Research Support Francisco M. Marty, MD, SM, AlloVir: Advisor/Consultant|Amplyx: Advisor/Consultant|Amplyx: Grant/Research Support|Ansun: Grant/Research Support|Avir: Advisor/Consultant|Chimerix: Grant/Research Support|Cidara: Grant/Research Support|F2G: Advisor/Consultant|F2G: Grant/Research Support|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|Kyorin: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Regeneron: Advisor/Consultant|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Scynexis: Grant/Research Support|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|United Medical: Advisor/Consultant|WHISCO: Grant/Research Support.

Something that still remains an issue to this day is how students and other individuals can become educated in matters that are generally taught in person and are difficult to translate to an online environment in particular [5]. In particular, teaching how to operate lab equipment without having hands-on experience is incredibly difficult. With the COVID-19 pandemic, the need for sufficient online learning materials and tools has become much greater in recent years [6]. To resolve this issue, a simulation was made in Unity that aims to educate its users on how to work with a microscope [7]. Sliders are provided in the simulation to control the X-axis, Yaxis, Z-axis, and focus. The simulation was tested for its effectiveness by gathering fifteen participants to download and test the simulation, then asking each participant to fill out a survey. In the survey, the participants graded the educational value and convenience of using the application on a scale from one to ten, and they were encouraged to leave any other feedback in a free-response section of the survey [8]. Results indicated that the general public would find this simulation practical in daily life, as participants generally rated the simulation as both educational and convenient to use.