Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Pulmonary electrical impedance tomography (EIT), a noninvasive, continuous, dynamic, and radiation-free bedside imaging technique for monitoring pulmonary ventilation, is now widely utilized in the diagnosis and management of critically ill patients. Beyond ventilation monitoring, hypertonic saline contrast-enhanced EIT for bedside pulmonary perfusion assessment has recently garnered significant attention. This article describes the application of hypertonic saline contrast-enhanced EIT to evaluate pulmonary perfusion in two patients following pulmonary endarterectomy, providing a reference for its perioperative application in such patients.

Objective The volume and cortical thickness of gray matter in patients with multiple sclerosis (MS) and neuromyelitis optica (NMO) were compared and analyzed by voxel⁃based morphometry (VBM) and surface⁃based morphometry (SBM), and the differences in the structural changes of gray matter in the two diseases were discussed. Methods A total of 21 MS patients, 16 NMO patients and 19 healthy controls were scanned by routine MRI sequence. The data were processed and analyzed by VBM and SBM method based on the statistical parameter tool SPM12 of Matlab2014a platform and the small tool CAT12 under SPM12. Results Compared with the normal control group (NC), after Gaussian random field (GRF) correction, the gray matter volume in MS group was significantly reduced in left superior occipital, left cuneus, left calcarine, left precuneus, left postcentral, left central paracentral lobule, right cuneus, left middle frontal, left superior frontal and left superior medial frontal (P<0. 05). After family wise error (FWE) correction, the thickness of left paracentral, left superiorfrontal and left precuneus cortex in MS group was significantly reduced (P<0. 05). Compared with the NC group, after GRF correction, the gray matter volume in the left postcentral, left precentral, left inferior parietal, right precentral and right middle frontal in NMO group was significantly increased (P<0. 05). In NMO group, the volume of gray matter in left middle occipital, left superior occipital, left inferior temporal, right middle occipital, left superior frontal orbital, right middle cingulum, left anterior cingulum, right angular and left precuneus were significantly decreased (P<0. 05). Brain regions showed no significant differences in cortical thickness between NMO groups after FWE correction. Compared with the NMO group, after GRF correction, the gray matter volume in the right fusiform and right middle frontal in MS group was increased significantly(P<0. 05). In MS group, the gray matter volume of left thalamus, left pallidum, left precentral, left middle frontal, left middle temporal, right pallidum, left inferior parietal and right superior parietal were significantly decreased (P<0. 05). After FWE correction, the thickness of left inferiorparietal, left superiorparietal, left supramarginal, left paracentral, left superiorfrontal and left precuneus cortex in MS group decreased significantly (P<0. 05). Conclusion The atrophy of brain gray matter structure in MS patients mainly involves the left parietal region, while NMO patients are not sensitive to the change of brain gray matter structure. The significant difference in brain gray matter volume between MS patients and NMO patients is mainly located in the deep cerebral nucleus mass.

Objective To construct reference ranges of cardiac size and morphologic parameters in low-risk fetuses at 28-39 gestational weeks using two-dimensional speckle tracking technique.Methods A prospective collection of 453 low-risk singleton pregnancies with echocardiography at Obstetrics and Gynecology Hospital,Fudan University was used to assess the size(length,width,and area)and morphology(sphericity index,i.e.,the ratio of length to width)of the fetal four-chamber view and two ventricles using two-dimensional speckle tracking technique.Repeated inter-and intra-observer agreement of measurements was assessed using the intraclass correlation coefficients(ICCs).Statistical analysis of cardiac measurement parameters was performed to establish reference ranges of values for cardiac size and morphology in low-risk fetuses.Results The inter-and intra-group ICCs for reproducibility tests of fetal cardiac parameters measurements were 0.691 to 0.980.Fetal four-chamber view and ventricular size increased with gestational week(all P<0.001),the end-diastolic length of the left ventricle was larger than that of the right ventricle,and the end-diastolic diameter was smaller than that of the right ventricle(both P<0.001),while there was no significant difference in the end-diastolic area of the two ventricles(P= 0.050).The spherical index of four-chamber view did not correlate with gestational week(P=0.811).The sphericity index of the basal and intermediate segments of the left ventricle was greater than that of the right ventricle,and the sphericity index of the apical segment was less than that of the right ventricle,the differences were statistically significant(all P<0.01).Conclusion The two-dimensional speckle tracking technique for measuring fetal cardiac parameters has good reproducibility.The reference ranges for cardiac size and morphology in low-risk fetuses developed in this study will be useful for prenatal evaluation of cardiac remodeling.

AIM To study the extraction process,enzymatic properties and practical application of glucuronic hydrolase in Scutellaria baicalensis stems and leaves(sbsl GUS).METHODS With granularity,water consumption,extraction time and extraction frequency as influencing factors,enzymatic activity as an evaluation index,the extraction process was optimized by orthogonal test on the basis of single factor test.The relationship between substrate(baicalin)concentration and enzymolysis rate,after which Vmax and Km were calculated,the effects of pH value,temperature and metal ion on enzymatic activity were investigated,pH stability and heat stability were evaluated.sbsl GUS was adotped in the enzymolysis of baicalin to prepare baicalein,then the effects of pH value,temperature,reaction time,initial substrate concentration and enzyme addition on transfer rate were investigated.RESULTS The optimal extraction process was determined to be 40 mesh for granularity,10 times for water consumption,15 min for extraction time,and 3 times for extraction frequency.The enzymolysis accorded with the kinetics of enzymatic reaction,Km was 0.006 3 mol/L,Vmax was 70.42 μmol/h,the strongest enzymatic activity was found at the pH value of 6.0,temperature of 45℃and metal ion of 100 mmol/L Cu2+,sbsl GUS demonstrated good stability at the ranges of 4.0-7.0 for pH value and 4-30℃for temperature.The optimal preparation process was determined to be 6.0 for pH value,45℃for temperature,more than 12 h for reaction time,67.2 mmol/L for initial substrate concentration,and 1 mL/0.269 mmol baicalin for enzyme addition,the transfer rate was 97.83%.CONCLUSION sbsl GUS enzymolysis exhibits high efficiency and mild condition,which can provide a simple preparation method for obtaining baicalein,and expand the application path of Scutellaria baicalensis stems and leaves.

As the predominant toxic constituent within the Aconitum genus, Aconitum alkaloids (ATs) exhibit both significant pharmaceutical value and substantial toxicity, have been widely used in traditional Chinese medicine and the realm of contemporary clinical medicine. However, owing to their high toxicity, inappropriate employment of ATs in pharmaceuticals, edibles, and the environment will pose serious threats to human health, inciting a series of toxic incidents. Consequently, it is very important to develop effective analytical methods. This paper presents a comprehensive review of the advancements in research pertaining to the pretreatment and detection methods in common substrates, including high performance liquid chromatography, liquid chromatography-mass spectrometry and rapid detection methods. To explore the specific sources of ATs in actual poisoning cases, the comprehensive traceability strategy based on plant morphology, chemical fingerprint analysis and DNA barcoding technology was discussed, proposing a comprehensive prospect for the development of ATs analysis and traceability, in order to provide guidance for related research within the forensic science domain.

Objective With the widespread of transcatheter aortic valve replacement(TAVR)in patients with severe symptomatic aortic stenosis(AS),the life-cycle management has become a major determinant of prognosis.Methods A total of 408 AS patients who underwent successfully TAVR from June 2021 to August 2023 were consecutively enrolled in Hospital Valve Intervention Center.Patients were assigned to the Usual Care(UC)group between June 2021 and October 2022,while patients were assigned to the Heart Multi-parameter Monitoring(HMM)group between November 2022 and August 2023.The primary endpoint was defined as composite endpoint within 6 months post-TAVR,including all-cause death,cardiovascular death,stroke/transient ischemic attack,conduction block,myocardial infarction,heart failure rehospitalization,and major bleeding events.Secondary endpoints were the time interval(in hours)from event occurrence to medical consultation or advice and patient satisfaction.Statistical analysis was performed using Kaplan-Meier and multivariable Cox proportional hazards models.Results The incidence of primary endpoint in HMM group was significantly lower than that in UC group(8.9％vs.17.7％,P=0.016),the driving event was the rate of diagnosis and recognition of conduction block.The average time intervals from event occurrence to receiving medical advice were 3.02 h in HHM group vs.97.09 h in UC group(P＜0.001).Using cardiac monitoring devices and smart healthcare platforms provided significant improving in patients long-term management(HR 0.439,95％CI 0.244-0.790,P=0.006).Conclusions The utilization of cardiac monitoring devices and smart healthcare platforms effectively alerted clinical events and improved postoperative quality of life during long-term management post TAVR.

The objective of this study was to determine the frequency and resistance patterns of ESBL-producing E.coli in lambs with diarrhea in the Kashi area,Xinjiang.The findings may provide guidance for the prevention and control of clinical E.coli disease.We collected 385 samples of perianal feces from lambs with diarrhea in the Kashgar area.From these samples,we isolated 371 strains of E.coli.We then used the double-paper-sheet synergistic method to screen for ESBL-producing E.coli.Additionally,we conducted analyses to identify drug-resistance genes,analyze drug resistance,and study the phylo-typing of the screened strains.Of 371 E.coli strains,204 were identified as ESBL-producing strains.The prevalence rates of blaCTX-M,blaCTX-M-1G,blaCTX-M-9G,and bla TEM resistance genes was 67.65％,69.12％,30.39％,and 63.73％,respectively.All ESBL-pro-ducing strains were resistant to multiple drugs,with resistance rates ranging from 90.69％to 100％for eight specific drugs:ampicillin,cefotaxime,gentamicin,enrofloxacin,azithromy-cin,tetracycline,chloramphenicol,methotrexate,and amitrazine.The phylogenetic subgroups of the strains were distributed primarily in groups A and D.Among group A strains,41.11％exhibited resistance to ten drugs,whereas among group D strains,40％exhibited resistance to 11 drugs.ESBL-pro-ducing strains of Escherichia coli are the main pathogens cau-sing diarrhea in lambs in the Kashgar region;group A is the main group,and all groups are multi-drug resistant.

Objective:To establish a graded method to avoid mean fluorescence intensity(MFI)threshold of HLA Class I antibodies corresponding antigen,and the HLAMatchmaker program has been used to select the minimum mismatch value of donor-patient epitopes.Evaluate the application value of combining both methods in selecting HLA compatible platelets(PTL)for patients with immune platelet transfusion failure(IPTR)in improving platelet the corrected count increment(CCI).Methods:A total 7 807 PLT cross-matching compatible were performed by the solid-phase red cell adherence(SPRCA)method for 51 IPTR patients.The Luminex single antigen flow cytometry was used to detect HLA Class I antibodies in patients,and detected the MFI value for different specificity antigens of HLA Class I antibodies,was graded into strong positive group(MFI＞4 000,level 1),medium positive group(1 000＜MFI 4 000,2),weak positive group(500＜MFI≤1 000,3),and one negative control group(MFI≤500).The results of 7 807 SPRCA their negative/positive reaction wells were enrolled and statistically analyzed in different grades and the four groups,the statistical differences between the four groups were compared.Multiple applications for the select HLA Class I compatible donor events were made for patients in two cases,and HLAMatchmaker program was used to calculate the number of HLA Class I epitopes mismatches between the donors and patients.The donor with the minimum number of epitopes mismatches was selected,while avoiding the corresponding antigens of HLA Class I antibodies in levels 1 and 2,the provision of HLA compatible platelets for IPTR.After the transfusions,the CCI value of the platelet transfusion efficacy evaluation index was calculated,and the clinical evaluation of the transfusion effect was obtained through statistical analysis.Results:There were statistically significant differences in the positive results of SPRCA immunoassay among the strong positive group,medium positive group,and weak positive group of 51 IPTR patients with different specific of HLA-I class antibodies and corresponding antigens(all P＜0.001).The positive results showed a range from high to low,with strong positive group＞medium positive group＞weak positive group.There were a statistical difference among between the strongly positive or moderately positive groups and the negative control group(P＜0.001).There was no statistical difference between the weakly positive group and the negative control group(P＞0.05).The strong positive group was set as the corresponding specific HLA Class I site corresponding antigen grade 1 avoidance threshold,the medium positive group as the grade 2 avoidance thresholds,and the weak positive group as the grade 3 avoidance threshold.In the case of donor platelet shortage,it is not necessary to avoid the weak positive group.Avoiding the strategy of donor antigens and HLAMatchmaker program scores≤7 corresponding to HLA Class I antibodies of levels 1 and 2,with CCI values＞4.5 × 109/L within 24 hours,can obtain effective clinical platelet transfusion conclusions.Conclusion:When selecting HLA Class I compatible donors for IPTR patients,the grading avoids HLA Class I antibodies corresponding to donor antigens,and the donor selection strategy with the minimum scores of HLAMatchmaker program is comprehensively selected.The negative result confirmed by platelet cross-matching experiments has certain practical application value for improving platelet count in IPTR patients.

Objective:To analyze the clinical phenotype and gene mutation of a genetic coagulation factor Ⅻ(FⅫ)deficiency pedigree and explore the molecular pathogenesis.Methods:The activated partial thromboplastin time(APTT)and FⅫ activity(FⅫ:C)were detected by clotting method.The FⅫ antigen(FⅫ:Ag)was tested with ELISA.All exons and flanks of F12 gene were determined by Sanger sequencing.ClustalX-2.1-win,PROVEAN and Swiss-Pdb Viewer software were used to analyze the conservatism of amino acids at the mutant site,forecast whether the mutant amino acids were harmful and confirm the influence of the mutation on protein structure.Results:The APTT of the proband prolonged to 71.3 s.The FⅫ:C and FⅫ;Ag were decreased to 5％and 6％,respectively.There were two heterozygous missense mutations c.580G＞T and c.1681G＞A detected in exon 7 and exon 14 of F12 gene,resultingin p.Gly175Cys and p.Gly542Ser,severally.Proband's father carried the p.Gly175Cys heterozygous mutation,while mother,brother and daughter had the p.Gly542Ser heterozygous mutation.Software analysis showed that both Gly175 and Gly542 were conserved,the two mutations were harmful and when mutations had occurred,the corresponding sites affected the protein local structure.Conclusion:The p.Gly175Cys and p.Gly542Ser compound heterozygous mutations are the molecular pathogenesis of the hereditary coagulation FⅫ deficiency pedigree.The p.Gly175Cys mutation has been detected for the first time in the world.