At present,the drug substitutes represented by new psychoactive substances are gradually be-coming popular,leading to an increasing demand for identifying novel drugs with unknown structures in drug investigation.Nuclear magnetic resonance(NMR)spectroscopy is an important tool for ana-lyzing molecular structures.In the absence of standard substances,quantitative NMR(qNMR)can un-dertake the quantitative analysis of target substances in complex mixtures and has unique advantages in the research of new drugs and their precursor drugs.Due to the limitations of the site and mainte-nance costs,as well as relatively complex operation,high-field superconducting NMR is less com-monly applied in drug research.The desktop low-field NMR developed in recent years provides a new alternative solution.Due to the use of permanent magnets,its size is reduced,and the operation and maintenance costs are lowered.It has been widely used in various research fields.This article reviews the development of low-field NMR technology,summarizes the application of desktop low-field NMR in screening and identification of suspicious substances,rapid content determination,analysis of drug manufacturing processes and synthetic routes,and correlation traceability.It also looks forward to the prospects and development directions of this technology in drug research,aiming to provide a reference for researchers who work in analytical chemistry and drug research.

Objective To investigate the effects of estrogen signaling on T-cell recruitment and polarization in acutely injured skeletal muscle.Methods One hundred C57BL/6 male mice,one hundred and eighty C57BL/6 female mice were selected.Twenty-five female mice were ovariectomized(OVX)and 10 male mice were taken as the sham-operated(sham).Then,cardiotoxin(CTX)induced tibialis anterior(TA)injury for preparing mice myoinjury model.Subcutaneous injection of 17β-estradiol(E2)or estrogen receptor antagonist 4-hydroxytamoxifen(4-OHT)was performed.A total of 140 mice(70 males and 70 females)were divided into four group including:PBS-male,CTX-male,PBS-female,and CTX-female.Serum estradiol(E2)levels were measured by ELISA,and muscle injury models were validated via HE staining.Subsequently,20 male and 20 female mice were selected for immunofluorescence(IF)and Real-time PCR to assess estrogen receptors(ER)expression in injured muscle tissue.Further,10 male and 40 female mice were allocated into five experimental groups,including CTX,CTX+E2,CTX+4-OHT,CTX+OVX,CTX+sham.HE staining and IF were performed to evaluate inflammatory infiltration in the injured muscle.Additionally,50 female mice were divided into CTX and CTX+OVX groups,and IF combined with flow cytometry were used to analyze T-cell phenotypes and muscle fiber regeneration in the injured muscle.Results In vivo,serum E2 and myofiber ERβ increased post-injury in mice of both sexes,significantly higher in females.Compared to the control group,E2 alleviated inflammation,OVX exacerbated inflammation,increased CD4+T-cell infiltration,elevated T helper 1 cell(Th1)response,decreased regulatory T cells(Tregs),impaired regeneration.In vitro,IFN-γ/LPS significantly upregulated ERβ in myotubes.Conclusion Estrogen signaling critically regulates muscle inflammation.Estrogen deficiency(OVX)delays repair of skeletal muscle by promoting Th1 response and suppressing Tregs function.

Objective To explore the pharmacokinetic changes of single dose of fentanyl in rats in a simulated high-altitude and contributing factors.Methods Thirty-six healthy female SD rats(6～8 weeks old,250±20 g)were randomly divided into high-altitude-acute-exposure group(group A),high-altitude-chronic-exposure group(group S)and control group(group C)through random number table,with 12 rats in each group.The group A and S were housed in a low-pressure chamber simulating the high altitude of 5000 m above sea level for 3 and 30 d respectively,and the group C was housed out of the chamber(at an altitude of 300 m).A single dose of fentanyl was administered through the femoral vein to 6 rats randomly selected from each group.Liquid chromatography tandem mass spectrometry(LC-MS/MS)was used to detect blood concentrations of fentanyl and WinNonlin 8.2 software was used to calculate the pharmacokinetic parameters,while blood samples were taken through the femoral artery before and in 1,2,4,8,15,30,60,120 and 180 min after administration.The remaining 6 rats were ultrasonographically assessed for portal vein internal diameter(PVD),peak flow velocity(PVV)and blood flow(PVF),and liver tissues were collected for CYP3A1 protein content assay.Results The blood drug concentrations of fentanyl in the group A and group S were significantly lower than those in the group C at 60,120,and 180 min(P=0.002,P＜0.001,P= 0.001).Compared with the group C,the clearance rate(CL)of the group A was increased by 54.06%(P=0.021),and the mean residence time(MRTlast)was shortened by 24.21%(P=0.033);CL of the group S was increased by 50.10%(P=0.041),the area under the concentration-time curve(AUC0-t,AUC0-∞)and MRTlast were reduced by 18.92%(P=0.039),27.54%(P=0.018)and 33.61%(P= 0.004),respectively.PVD and PVF in the group S increased by 10.87%(P=0.006)and 42.50%(P= 0.006)when compared with the group C.The CYP3A1 protein content in the group A was 28.74%,which was higher than that in the group C(P=0.048).Conclusion Fentanyl is cleared significantly faster after a single dose in rats in simulated high-altitude,which may be related to the increased liver blood flow and increased CYP3A1 protein expression in liver.

The genomic characteristics and cellular tropism of a Mangshi virus(MSV)isolated in China were investigated,thereby establishing a robust foundation for further research on the evolution and pathogenicity of MSV.The genome sequence of MSV strain V301/YNJH/2019 was obtained by next-generation sequencing,followed by phylogenetic tree construction and rearrangement assessment using software IQtree,RPD4,and Simplot.Viral proliferation was assessed in C6/36(Aedes albop-ictus),Vero(African green monkey kidney),and BHK(baby hamster kidney)cells.An initial epidemiological investigation of MSV in local cattle and goats was conducted using the serum neutralization test.The genome of MSV strain V301/YNJ H/2019 was 20623 bp in length,encompassing 12 segments of double-stranded RNA(Seg-1 to Seg-12).Sequence analysis confirmed genomic rearrangement of the Seg-1 and Seg-11 sequences,ex-hibiting high similarity to MSV isolated from lake sediment in China in 2022,while Seg-2 to Seg-10 and Seg-12 were most closely related to a MSV strain isolated from mosquitoes in China in 2013.The virus efficiently proliferated and induced sig-nificant cytopathic effects(CPE)in both C6/36 and BHK cells,but limited replication and no observable CPE in Vero cells.No detectable neutralizing antibodies against MSV were detected in 20 goat serum samples collected in Mangshi,while 2 of 20 bo-vine serum samples were positive with neutralizing antibody titers of 1:128 and 1:54.Whole genome sequencing revealed re-assortment events of the V301/YNJH/2019 strain,which is capable of infecting C6/36,BHK,and Vero cells.MSV infection was confirmed in cattle in Mangshi.

Objective:To analyze the risk factors for late-onset hemorrhagic cystitis(LOHC)after allogeneic hematopoietic stem cell transplantation(allo-HSCT),the risk factors for the progression of LOHC to severe LOHC,and the effect of LOHC on survival.Methods:The clinical data of 300 patients who underwent allo-HSCT at the First Affiliated Hospital of Chongqing Medical University from January 2015 to December 2021 were retrospectively analyzed.The relevant clinical parameters that may affect the occurance of LOHC after allo-HSCT were selected for univariate and multivariate analysis.Then,the differences in overall survival(OS)and progression-free survival(PFS)between different groups were analyzed.Results:The results of multivariate analysis showed that the independent risk factors for LOHC after allo-HSCT were as follows:age≤45 years old(P=0.039),intensified conditioning regimen with fludarabine/cladribine and cytarabine(P=0.002),albumin ≤ 30 g/L on d30 after transplantation(P=0.007),CMV-DNA positive(P=0.028),fungal infection before transplantation(P=0.026),and the occurrence of grade Ⅱ-Ⅳ aGVHD(P=0.006).In the transplant patients who have already developed LOHC,the occurance of LOHC within 32 days after transplantation(P=0.008)and albumin ≤ 30 g/L on d30 after transplantation(P=0.032)were independent risk factors for the progression to severe LOHC.The OS rate of patients with severe LOHC was significantly lower than that of patients without LOHC(P=0.041).Conclusion:For the patients aged ≤ 45 years old and with intensified conditioning regimen,it is necessary to be vigilant about the occurrence of LOHC;For the patients with earlier occurrence of LOHC,it is necessary to be vigilant that it develops into severe LOHC.Early prevention and treatment of LOHC are essential.Regular monitoring of CMV-DNA and albumin levels,highly effective antiviral and antifungal therapies,and prevention of aGVHD are effective measures to prevent the occurrence and development of LOHC.

Objective:To analyze the risk factors of primary poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid malignancies and the impact of primary PGF on survival. Methods:The clinical data of 146 patients with myeloid malignancies who underwent allo-HSCT in our hospital from January 2015 to December 2021 were retrospectively studied. Some relevant clinical parameters which may affect the development of primary PGF after allo-HSCT were selected for univariate and multivariate analysis,as well as performed survival analysis. Results:A total of 9 patients (6.16％) were diagnosed with primary PGF,and their medium age was 37(28-53) years old. Among them,1 case underwent matched sibling donor HSCT,1 case underwent matched unrelated donor HSCT,and 7 cases underwent HLA-haploidentical related donor HSCT. Moreover,5 cases were diagnosed as cytomegalovirus (CMV) infection,and 3 cases as Epstein-Barr virus (EBV) infection. Univariate and multivariate analysis showed that CD34+cell dose<5×106/kg and pre-transplant C-reactive protein (CRP)>10 mg/L were independent risk factors for occurrence of the primary PGF after allo-HSCT in patients with myeloid malignancies. The 3-year overall survival (OS) rate of primary PGF group was 52.5％,which was significantly lower than 82.8％ of good graft function group (P<0.05). Conclusion:Making sure pre-transplant CRP≤10 mg/L and CD34+cell dose ≥5×106/kg in the graft may have an effect on preventing the occurrence of primary PGF after allo-HSCT. The occurrence of primary PGF may affect the OS rate of transplant patients,and early prevention and treatment are required.

Objective The researchers systematically retrieved,evaluated,and summarized the best evidence for the care of nebulized inhalation in adult patients on mechanical ventilation,to provide a basis for standardizing the care of nebulized inhalation in patients on mechanical ventilation.Methods We systematically searched the domestic and foreign databases to collect the evidence on the literature related to nebulization therapy for mechanical ventilation in adults.The time for the retrieval is from the inception of databases until February 2023.There were 3 researchers who evaluated the quality of the literature,and extracted and summarized the evidence based on this subject.Results A total of 19 articles were obtained in database.42 pieces of evidence were summarized,covering pre-assessment of nebulized inhalation,preparation before nebulized inhalation,medication management,selection and standardized use of nebulization devices,respiratory machine mode and parameter settings,equipment management during nebulized inhalation,evaluation of effect,management of adverse reactions,disposal of materials and environment after nebulized inhalation and management of nebulized inhalation for respiratory infectious diseases.Conclusion This study summarized the best evidence for nebulized inhalation nursing in adult patients with mechanical ventilation,so as to provide a reference of standardized nebulized inhalation therapy for such patients,which is conducive to ensuring the safety of patients.

Objective To investigate the effects of exercise and complex environment on lipopolysaccharide(LPS)-induced dopaminergic neuron death in the substantia nigra of midbrain.Methods C57BL/6 mice were divided into control group,LPS group,LPS+swimming group and LPS+complex environment group,with 7 mice in each group.The mice in the LPS group were injected with LPS into the brain to establish an inflammatory model of Parkinson's disease and lived in cages for 2 weeks.Mice in LPS+swimming group were forced to swim for 15 minutes every day for 2 weeks after modeling.The mice in the LPS+complex environment group were placed in a complex environment for 2 weeks after modeling.The control group mice were not treated.After 14 days of modeling,behavioral experiments such as footprint,open field and rotating rod were performed on each group of mice to detect the autonomous exercise ability,exercise balance ability and depression level of mice.The expressions of tyrosine hydroxylase(TH)in substantia nigra was detected by immunohistochemical staining and Western blotting.The expressions of brain-derived neurotrophic factor(BDNF),Caspase-3,interleukin-1β(IL-1β),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in the substantia nigra of the midbrain were detected by Western blotting.The transcription levels of IL-1β,IL-6 and TNF-α in substantia nigra were detected by RT-PCR.Results Compared with the control group,the exercise ability and balance ability of mice in LPS group,LPS+swimming group and LPS+complex environment group decreased,the depression level increased(P＜0.001),the number of TH positive neurons and BDNF protein decreased significantly(P＜0.001),and the contents of Caspase-3,IL-1β,IL-6 and TNF-α increased significantly(P＜0.001).Compared with the LPS group,the exercise ability and balance ability of the mice in the LPS+swimming group and the LPS+complex environment group were restored,the depression level decreased significantly(P＜0.01),the survival number of TH positive neurons and the content of BDNF increased significantly(P＜0.01),Caspase-3,IL-1β,IL-6 and TNF-α reduced significantly(P＜0.01),and the phenomenon in the LPS+complex environment group was more significant.Conclusion Exercise and complex environment can inhibit LPS-induced central nervous system inflammation in mice,thereby reducing damage to midbrain substantia nigra neurons,and the inhibitory effect of LPS+complex environment group is more significant.

Objective To compare the effects of different dose prediction models of sufentanil in elderly hip arthroplasty with ultrasound-guided bow tie fascia iliac block.Methods A total of 90 elderly patients who underwent ultrasound-guided bow tie fascia iliac during hip arthroplasty in our hospital from June 2018 to June 2022 were selected.The dose of sufentanil was determined by a linear regression(ALR),multiple linear regression(MLR)or deep belief networks(DBN).Patients were randomly divided into the ALR group,the MLR group and the DBN group,with 30 cases in each group.The analgesic effect,hemodynamic index,inflammatory factor level and surgical index were compared among all groups.Kaplan-Meier method was used to analyze the incidence of hip infection 2 weeks after surgery in each group.Results There was no significant difference in the gender,age,body weight,American Society of Anesthesiologists(ASA)classification or complications among all groups(P>0.05).The Harris score 24 hours after surgery and duration of sensory block in the DBN group were higher/longer than those in the ALR group,numerical rating scale(NRS)score 24 hours after surgery,mean arterial pressure(MAP)and heart rate(HR)at the beginning of surgery and 30 minutes after surgery,levels of interleukin-17(IL-17)and tumor necrosis factor-α(TNF-α)24 hours after surgery,onset time of sensory block,and number of patient controlled analgesia(PCA)compression were lower/earlier/less than those in the ALR group,the modified observer's assessment of alertness/sedation scale(OAA/S)score 24 hours after surgery was significantly lower than those in the ALR group and the MLR group,with statistically significant differences(P<0.05).Harris score 24 hours after surgery and duration of sensory block in the MLR group were higher/longer than those in the ALR group,modified OAA/S score 12 hours after surgery,MAP 30 minutes after surgery,levels of IL-17 and TNF-α 24 hours after surgery,onset time of sensory block,and the number of PCA compressions were lower/longer/less than those in the ALR group,with statistically significant differences(P<0.05).Kaplan-Meier analysis showed that there were significant differences in the incidences of hip infection 2 weeks after surgery among all groups(P<0.05),and there were significant differences in the incidences of hip infection 2 weeks after surgery between the ALR group and the DBN group(P<0.05).Conclusion The effectiveness of calculating the dose of sufentanil using the MLR and DBN in elderly hip arthroplasty with bow tie fascia iliac block is better than that of ALR,and the advantage of DBN is more obvious.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.