Objective To investigate the global burden of visceral leishmaniasis (VL) from 1990 to 2021 and predict the trends in the burden of VL from 2022 to 2035, so as to provide insights into global VL prevention and control. Methods The global age-standardized incidence, prevalence, mortality and disability-adjusted life years (DALYs) rates of VL and their 95% uncertainty intervals (UI) were captured from the Global Burden of Disease Study 2021 (GBD 2021) data resources. The trends in the global burden of VL were evaluated with average annual percent change (AAPC) and 95% confidence interval (CI) from 1990 to 2021, and gender-, age-, country-, geographical area- and socio-demographic index (SDI)-stratified burdens of VL were analyzed. The trends in the global burden of VL were projected with a Bayesian age-period-cohort (BAPC) model from 2022 to 2035, and the associations of age-standardized incidence, prevalence, mortality, and DALYs rates of VL with SDI levels were examined with a smoothing spline model. Results The global age-standardized incidence [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)], prevalence [AAPC = -0.06%, 95% CI: (-0.06%, -0.06%)], mortality [AAPC = -0.25%, 95% CI: (-0.25%, -0.24%)] and DALYs rates of VL [AAPC = -2.38%, 95% CI: (-2.44%, -2.33%)] all appeared a tendency towards a decline from 1990 to 2021, and the highest age-standardized incidence [2.55/10⁵, 95% UI: (1.49/10⁵, 4.07/10⁵)], prevalence [0.64/10⁵, 95% UI: (0.37/10⁵, 1.02/10⁵)], mortality [0.51/10⁵, 95% UI: (0, 1.80/10⁵)] and DALYs rates of VL [33.81/10⁵, 95% UI: (0.06/10⁵, 124.09/10⁵)] were seen in tropical Latin America in 2021. The global age-standardized incidence and prevalence of VL were both higher among men [0.57/10⁵, 95% UI: (0.45/10⁵, 0.72/10⁵); 0.14/10⁵, 95% UI: (0.11/10⁵, 0.18/10⁵)] than among women [0.27/10⁵, 95% UI: (0.21/10⁵, 0.33/10⁵); 0.06/10⁵, 95% UI: (0.05/10⁵, 0.08/10⁵)], and the highest mortality of VL was found among children under 5 years of age [0.24/10⁵, 95% UI: (0.08/10⁵, 0.66/10⁵)]. The age-standardized incidence (r = -0.483, P < 0.001), prevalence (r = -0.483, P < 0.001), mortality (r = -0.511, P < 0.001) and DALYs rates of VL (r = -0.514, P < 0.001) correlated negatively with SDI levels from 1990 to 2021. In addition, the global burden of VL was projected with the BAPC model to appear a tendency towards a decline from 2022 to 2035, and the age-standardized incidence, prevalence, mortality and DALYs rates were projected to be reduced to 0.11/10⁵, 0.03/10⁵, 0.02/10⁵ and 1.44/10⁵ in 2035, respectively. Conclusions Although the global burden of VL appeared an overall tendency towards a decline from 1990 to 2021, the burden of VL showed a tendency towards a rise in Central Asia and western sub-Saharan African areas. The age-standardized incidence and prevalence rates of VL were relatively higher among men, and the age-standardized mortality of VL was relatively higher among children under 5 years of age. The global burden of VL was projected to continue to decline from 2022 to 2035.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

Objective To investigate the spatial distribution of Aedes albopictus in China at different time periods from 2000 to 2019, so as to provide insights into precise management of Ae. albopictus in China. Methods Data pertaining to the distribution of Ae. albopictus in China from 2000 to 2019 were collected through literature retrieval with terms of “Aedes albopictus”, “monitoring”, “survey”, “density”, “distribution”, and “outbreak” in national and international databases. The title and time of the publication, sampling sites, sampling time, mosquito capture methods, and mosquito species and density were extracted, and the longitude and latitude of sampling sites were obtained through Baidu Map. Meteorological element data at meteorological observation stations within China were obtained from the National Climatic Data Center of the United States, and the annual maximum temperature, annual minimum temperature, average temperature in January, average temperature in July, annual temperature range, daily temperature range and relative humidity were calculated and subjected to Kriging interpolation. Monthly cumulative precipitation grid data and monthly average temperature grid data with a resolution of 1 km for China from 2000 to 2019 were obtained from the National Tibetan Plateau Scientific Data Center, and the annual precipitation and annual average temperature were calculated cumulatively. Population density data in China from 2000 to 2019 were obtained from the WorldPop Hub, and the gross domestic product (GDP) in China was obtained from the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences. The above data were divided into 5-year intervals to calculate data during the periods from 2000 to 2004, from 2005 to 2009, from 2010 to 2014, and from 2015 to 2019. Ae. albopictus distribution data were modeled in China from 2000 to 2019 and during each period with the classification random forest (RF) model, to predict the distribution of Ae. albopictus across the country and analyze the distribution of Ae. albopictus based on the seven major climate zones in China. The performance of RF models was evaluated by accuracy, precision, recall, and area under the receiver operating characteristic curve (AUC), and the importance of each feature in the RF model was evaluated with mean decrease accuracy (MDA). Results A total of 1 191 Chinese publictions and 391 English publications were retrieved, among which 580 articles provided detailed data on the sampling sites of Ae. albopictus and specific sampling years, meeting the inclusion criteria. A total of 2 234 Ae. albopictus sampling sites were included in China from 2000 to 2019, and RF modeling results showed that the overall Ae. Albopictus distribution area was mainly found in southeastern and southwestern provinces of China from 2000 to 2019, with scattered distribution in coastal areas of northeastern provinces, such as Liaoning Province. The accuracy, precision, recall and AUC of the RF model were 0.915 to 0.947, 0.933 to 0.975, 0.898 to 0.978, and 0.902 to 0.932 for the distribution of Ae. albopictus at different time periods from 2000 to 2019. Among all features in the RF models, population density was the most contributing factor to the distribution of Ae. albopictus in China, followed by GDP, and all meteorological variables contributed relatively less to the predictive power of the RF model. In China’s seven major climate zones, Ae. albopictus was almost entirely distributed in the marginal tropical humid region, the north subtropical humid region, and the warm temperate semi-humid region. The combined distribution area of these three zones accounted for 100.0% of the national distribution area from 2000 to 2004, from 2005 to 2009, and from 2010 to 2014, and 99.9% from 2015 to 2019, and the proportion of Ae. albopictus distribution area in the warm temperate semihumid region increased gradually from 20.2% to 30.2%. Conclusions Ae. albopictus is mainly distributed in the southeastern and southwestern provinces of China and is greatly influenced by population and economic factors. The warm temperate semi-humid region in China is gradually becoming a hot spot for the distribution of Ae. albopictus.

In cases where a tracheal injury exceeds half the length of the adult trachea or one-third of the length of the child trachea, it becomes difficult to perform end-to-end anastomosis after tracheal resection due to excessive tension at the anastomosis site. In such cases, tracheal replacement therapy is required. Advances in tissue engineering technology have led to the development of tissue engineering tracheal substitutes, which have promising applications. Hydrogels, which are highly hydrated and possess a good three-dimensional network structure, biocompatibility, low immunogenicity, biodegradability, and modifiability, have had wide applications in the field of tissue engineering. This article provides a review of the characteristics, advantages, disadvantages, and effects of various hydrogels commonly used in tissue engineering trachea in recent years. Additionally, the article discusses and offers prospects for the future application of hydrogels in the field of tissue engineering trachea.

ObjectiveTo construct an animal model of respiratory syncytial virus（RSV）-infected pneumonia suitable for preclinical studies. MethodsThe virulence of RSV to the four cell lines was observed by cytopathic effect （CPE）， and 50% tissue culture infective dose（TCID₅₀） was calculated. Twenty BALB/c mice were randomly divided into a normal group and a model group. Six BALB/c-hIGF1R mice served as the humanized IGF1R model group. Except for the normal group， the other groups received intranasal RSV infection on days 1 and 3 to establish a viral pneumonia model. The efficacy of establishing an RSV-induced pneumonia animal model based on humanized insulin-like growth factor 1 receptor （IGF1R） mice was evaluated by measuring organ indices， peripheral blood lymphocyte percentages， pulmonary pathology and imaging， and pulmonary viral load. Additionally， ten BALB/c mice served as normal group， and thirty-two BALB/c-hIGF1R mice were randomly assigned to humanized IGF1R model group， ribavirin group （82.5 mg·kg^-¹·d^-¹）， and high and low dose groups of Lianhua Qingwen （3.3 mg·kg^-¹·d^-¹ ， 1.65 mg·kg^-¹·d^-¹）， with 8 mice per group. The viral load in lung tissue was measured after ribavirin and Lianhua Qingwen intervention， and the model was applied to the evaluation of anti-RSV drugs. ResultsIn the lungs of the humanized IGF1R model group， large solid and diffuse ground-glass shadows were seen， and the lung volume was significantly increased （P<0.01）. The lung index was significantly increased （P<0.01）， and both the spleen index and thymus index were significantly decreased （P<0.01）. The percentages of CD3⁺ and CD4⁺T cells were significantly decreased （P<0.05）， and there was a large amount of inflammation and stasis in the perivascular area of the lung tissue， which was predominantly characterized by lymphocytes. The endothelium of blood vessels was partially detached， with a small number of eosinophils. After infecting BALB/c-hIGF1R mice with RSV， the expression of viral nucleic acids in the lung tissue of the mice was significantly increased， with significant differences compared with the normal group （P<0.01）. The expression of viral nucleic acids in the ribavirin group and the high and low dose groups of Lianhua Qingwen was significantly reduced， with significant differences compared with the normal group （P<0.01）. ConclusionHumanized IGF1R mice are more susceptible to respiratory SVC， and the animal model of RSV-infected pneumonia based on humanized IGF1R mice was successfully constructed， which is suitable for the evaluation of anti-RSV drugs.

ObjectiveTo construct an animal model of respiratory syncytial virus（RSV）-infected pneumonia suitable for preclinical studies. MethodsThe virulence of RSV to the four cell lines was observed by cytopathic effect （CPE）， and 50% tissue culture infective dose（TCID₅₀） was calculated. Twenty BALB/c mice were randomly divided into a normal group and a model group. Six BALB/c-hIGF1R mice served as the humanized IGF1R model group. Except for the normal group， the other groups received intranasal RSV infection on days 1 and 3 to establish a viral pneumonia model. The efficacy of establishing an RSV-induced pneumonia animal model based on humanized insulin-like growth factor 1 receptor （IGF1R） mice was evaluated by measuring organ indices， peripheral blood lymphocyte percentages， pulmonary pathology and imaging， and pulmonary viral load. Additionally， ten BALB/c mice served as normal group， and thirty-two BALB/c-hIGF1R mice were randomly assigned to humanized IGF1R model group， ribavirin group （82.5 mg·kg^-¹·d^-¹）， and high and low dose groups of Lianhua Qingwen （3.3 mg·kg^-¹·d^-¹ ， 1.65 mg·kg^-¹·d^-¹）， with 8 mice per group. The viral load in lung tissue was measured after ribavirin and Lianhua Qingwen intervention， and the model was applied to the evaluation of anti-RSV drugs. ResultsIn the lungs of the humanized IGF1R model group， large solid and diffuse ground-glass shadows were seen， and the lung volume was significantly increased （P<0.01）. The lung index was significantly increased （P<0.01）， and both the spleen index and thymus index were significantly decreased （P<0.01）. The percentages of CD3⁺ and CD4⁺T cells were significantly decreased （P<0.05）， and there was a large amount of inflammation and stasis in the perivascular area of the lung tissue， which was predominantly characterized by lymphocytes. The endothelium of blood vessels was partially detached， with a small number of eosinophils. After infecting BALB/c-hIGF1R mice with RSV， the expression of viral nucleic acids in the lung tissue of the mice was significantly increased， with significant differences compared with the normal group （P<0.01）. The expression of viral nucleic acids in the ribavirin group and the high and low dose groups of Lianhua Qingwen was significantly reduced， with significant differences compared with the normal group （P<0.01）. ConclusionHumanized IGF1R mice are more susceptible to respiratory SVC， and the animal model of RSV-infected pneumonia based on humanized IGF1R mice was successfully constructed， which is suitable for the evaluation of anti-RSV drugs.

A derivatizaton method combined with gas chromatography-mass spectrometry(GC-MS)was established for detection of isobutyl chloroformate(IBCF)residue in active pharmaceutical ingredient of agatroban.The extraction and derivatization reagents,derivatization time,qualitative and quantitative ions were selected and optimized,respectively.The possible mechanism of derivatization and characteristic fragment ions fragmentation were speculated.The agatroban samples were dissolved and extracted by methanol,and the residual IBCF was derived with methanol to generate methyl isobutyl carbonate(MIBCB).After 24 h static derivatization at room temperature,IBCF was completely transformed into MIBCB,which could be used to indirectly detect IBCF accurately.The results showed that the linearity of this method was good in the range of 25-500 ng/mL(R2=0.9999).The limit of detection(LOD,S/N=3)was 0.75 μg/g,and the limit of quantification(LOQ,S/N=10)was 2.50 μg/g.Good recoveries(95.2%-97.8%)and relative standard deviations(RSDs)less than 3.1%(n=6)were obtained from agatroban samples at three spiked levels of IBCF(2.50,25.00,50.00 μg/g),which showed good accuracy of this method.Good precision of detection results was obtained by different laboratory technicians at different times,the mean value of spiked sample solution(25.00 μg/g)was 24.28 μg/g,and the RSD was 2.1%(n=12).The durability was good,minor changes of detection conditions had little effect on the results.Under the original condition and conditions with initial column temperature±5℃,heating rate±2℃/min,column flow rate±0.1 mL/min,the IBCF content of spiked sample solution(25.00 μg/g)was detected,the mean value of detection results was 24.16 μg/g,and the RSD was 2.2%(n=7).Eight batches of agatroban samples from two manufacturers were detected using the established method,and the results showed that no IBCF residue was detected in any of these samples.The agatroban samples could be dissolved by methanol,and then the IBCF residue could be simultaneously extracted and derived with methanol as well.This detection method had the advantages of simple operation,high sensitivity,low matrix effect and accurate quantification,which provided a new effective method for detection of IBCF residue in agatroban.

Objective To identify the clinical characteristics and prognostic factors of young patients with sporadic rectal cancer liver metastasis(RCLM).Methods The clinical data of young RCLM patients at 45 years or under(n=40,as younger patient group)in Peking University First Hospital from January 2016 to January 2021 were reviewed,meanwhile,elder RCLM patient group were comprised of 82 patients older than 45-year-old in a 1:2 ratio.Proportions of categorical variables were compared between young patients and old patients.The clinicopathologic parameters were analyzed with univariate and multivariate Cox regression models and Kaplan-Meier method for demonstrating survival differences between the maximum diameter of liver metastasis and local therapy.Results One hundred and twenty-two RCLM patients were identified,the 1-,3-and 5-year survival rates of young patient group were 97.5%,47.5%,15.0%,those of elder patient group were 84.1%,26.8%,9.8%,respectively.The differences in BMI(P=0.008),primary tumor with obstruction and bleeding(P=0.006),synchronous rectal cancer liver metastases(P=0.005),the maximum diameter of liver metastasis>3 cm(P=0.019)were statistically significant between the two groups.And univariate and multivariate analyses showed that age(P=0.003),N stage(P=0.007),local therapy for liver metastases(P=0.047)and the maximum diameter of liver metastasis(P=0.030)were independent risk factors for influencing the prognosis of RCLM patients;curative resection or not of primary tumor(P=0.035)and the maximum diameter of liver metastasis(P=0.041)were independent risk factors for influencing the prognosis of young RCLM patients.Kaplan-Maier curve demonstrated survival differences between the maximum diameter of liver metastasis and local therapy for liver metastasis in RCLM patients(log-rank P=0.000).Conclusions Although with later staging of initial tumor station,young RCLM patients may obtain better survival benefit compared with old patients.Higher degree of lymph node metastasis,local therapy for liver metastases and the maximum diameter of liver metastasis>3 cm indicates poor prognosis in RCLM patients,and without curative resection of primary tumor and maximum diameter of liver metastasis are also considered as the independent poor prognostic factors of young RCLM patients.Local therapy for liver metastases appears to play an important role in the treatment strategy of RCLM patients.

Objective To investigate the genetic risk factors of deep vein thrombosis(DVT)after trauma.Methods In a nested case-control study,50 patients with DVT after traumatic lower extremity fractures and 50 patients without DVT were recruited.The two groups were matched with gender,age and fracture sites.Preoperative venography was performed to diagnose DVT in trauma patients.Genome wide association study(GWAS)was used to investigate the genetic risk factors for preoperative DVT after traumatic lower ex-tremity fractures.Genomic DNA in leukocytes from blood sample was extracted and used for GWAS.Results GWAS was conducted based on 2 662 single nucleotide variants(SNV)which were dispersed in 144 interested genes.Ten genes were found to have signifi-cant association with trauma-related DVT,including cofactors of hemostasis mechanism,i.e.,THBD,F5,SERPIND1 and ITGA2,the factors related to vitamin K-dependent(VKD)carboxylation,i.e.,GGCX and CALU,and the members of cytochrome P450 family,i.e.,CYP1A1,CYP3A4,CYP2C19 and CYP2B6.Conclusion DVT after trauma might be regulated by the cofactors of hemostasis mechanism,the factors related to VKD carboxylation and the members of cytochrome P450 family.The results of our study may provide reference and inspiration for genetic susceptibility of preoperative DVT after trauma.

BACKGROUND:Bone wax is a filler that can be used for bone hemostasis.Although modification of bone wax formulations is attempted worldwide,its inertness is still the main challenge today.There is an urgent clinical need to develop novel orthopedic hemostatic materials with hemostasis,osteogenesis and antibacterial properties. OBJECTIVE:To review the development of orthopedic hemostatic materials including bone wax and its substitutes. METHODS:PubMed,Web of Science,WanFang,CNKI and VIP databases were searched for literature related to bone wax,hemostatic materials,and research progress of orthopedic hemostatic materials,and 136 articles were selected for inclusion in the review by reading the abstracts of the articles in the initial screening. RESULTS AND CONCLUSION:To replace traditional bone wax,researchers have developed various orthopedic hemostatic materials based on the needs of practical scenarios such as hemostasis and osteogenesis.However,relevant studies mostly focus on basic physical and chemical and performance tests,lack a systematic evaluation system,and lack sufficient reports of large animal experiments and clinical trials.Therefore,bone wax is still a recognized orthopedic hemostatic material at present.The fundamental reason is that the design of existing materials cannot timely meet the new needs of intraoperative hemostasis,postoperative osteogenesis and clinical practice.In the future,the structure,composition and function of existing hemostatic and osteogenic materials need to be integrated and redesigned to meet the increasing demand for hemostatic and osteogenic materials.