Quantitative structure-retention relationship (QSRR) is an important tool in chromatography. QSRR examines the correlation between molecular structures and their retention behaviors during chromatographic separation. This approach involves developing models for predicting the retention time (RT) of analytes, thereby accelerating method development and facilitating compound identification. In addition, QSRR can be used to study compound retention mechanisms and support drug screening efforts. This review provides a comprehensive analysis of QSRR workflows and applications, with a special focus on the role of artificial intelligence-an area not thoroughly explored in previous reviews. Moreover, we discuss current limitations in RT prediction and propose promising solutions. Overall, this review offers a fresh perspective on future QSRR research, encouraging the development of innovative strategies that enable the diverse applications of QSRR models in chromatographic analysis.

Objective To explore the relationship between dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and clinical pathological features of invasive breast cancer and lymphovascular invasion(LVI).Methods Imaging and clinical pathological data were retrospectively collected from 508 patients with invasive breast cancer who underwent breast DCE-MRI at the First Medical Center of Chinese PLA General Hospital from January 2019 to August 2021.Patients were divided into the LVI-positive(LVI+)group(n=79)and LVI-negative(LVI-)group(n=429)based on postoperative pathological results.Univariate and multivariate logistic regression analyses were used to identify risk factors for LVI.Results Compared with LVI-group,LVI+group had a higher proportion of patients aged<45 years(44.3%vs.27.0%,P=0.002),non-mass-like enhancement(NME)(31.7%vs.17.7%,P=0.004),Ki-67 expression rate(40.0%vs.30.0%,P<0.001),high Ki-67 expression(94.9%vs.78.1%,P=0.001),Luminal B subtype(76.0%vs.60.1%,P=0.008),and positive axillary lymph nodes rate(72.2%vs.31.5%,P<0.001),while the proportion of Luminal A subtype was lower(2.5%vs.21.5%,P<0.001).Univariate and multivariate logistic regression analyses showed that age≥45 years(OR=0.468,95%CI 0.280-0.783,P=0.004)was an independent protective factor for LVI,while NME(OR=1.987,95%CI 1.126-3.444,P=0.016)was an independent risk factor.Compared with Luminal A subtype,patients with Luminal B subtype(OR=10.482,95%CI 3.164-64.923,P=0.001),HER-2 overexpression subtype(OR=11.571,95%CI 2.755-79.341,P=0.003)and triple-negative subtypes(OR=8.433,95%CI 1.985-57.908,P=0.009)had a higher risk of LVI.Conclusions Age≥45 years is an independent protective factor for LVI,while NME is an independent risk factor.Among molecular subtypes,patients with Luminal B,HER-2 overexpression and triple-negative subtypes have a higher risk of LVI compared with the Luminal A subtype.

Objective To investigate the effect and mechanism of proteasome inhibitor MG132 on memory impairment induced by chronic hypoxia in mice.Methods(1)A hypoxic model of the mouse midbrain dopaminergic neuron cell line MN9D was established using a hypoxia workstation.To observe the effects of hypoxia on the expression of TH,Ub-K48 and Ub-K63,MN9D cells were divided into normoxia group and hypoxia(12 h,24 h and 48 h)groups.To observe the effects of MG132 on the expression of the above-mentioned proteins,MN9D cells were divided into normoxia group,hypoxia group and hypoxia + MG132(25,50,100,200 μmol/L)group.(2)A mouse model of memory impairment was established using a hypobaric chamber.To observe the effects of hypobaric hypoxia on the expression of TH,Ub-K48 and Ub-K63 in the substantia nigra compacta(SNc)of mice,thirty C57BL/6 mice were randomly and equally divided into normoxia group and hypobaric hypoxia(3 d and 21 d)groups,10 in each group.To observe the effects of MG132 on spatial memory impairment induced by hypobaric hypoxia,twenty-four C57BL/6 mice were randomly and equally divided into normoxia group,hypobaric hypoxia 21 d group and hypobaric hypoxia 21 d+MG132 group,8 in each group.(3)The protein expression levels of TH,Ub-K48,and Ub-K63 in MN9D cells which were either subjected to different durations of hypoxia treatment or pre-treated with MG132 prior to hypoxia treatment were detected using Western blotting(WB).The novel object recognition test was used to detect the memory function of mice.Immunofluorescence was used to detect the proportion of positive immunoreactive area of TH response in the SNc region.The expression levels of TH,Ub-K48,and Ub-K63 in the SNc region were detected by WB.Results(1)Compared with normoxia group,MN9D cells in hypoxia 24 h group showed increasing expression of Ub-K48 and Ub-K63(P<0.05),and decreasing expression of TH(P<0.05),and MN9D cells in all hypoxia groups showed increasing expression of Ub-K48/TH and Ub-K63/TH(P<0.05).Compared with hypoxia group,MN9D cells showed decreasing expression of Ub-K48/TH and Ub-K63/TH in hypoxia + MG132 100 umol/L group and hypoxia + MG132 200 umol/L group(P<0.05).(2)Compared with the mice in normoxia group,mice in 3 d and 21 d hypobaric hypoxia groups showed decreasing expression of TH(P<0.001),and increasing expression of Ub-K48/TH and Ub-K63/TH(P<0.05)in the SNc region.Compared with normoxia group,the mice in 21 d hypobaric hypoxia group showed a lower new object recognition index(P<0.01),and the proportion of positive immunoreactive area of TH response in the SNc region(P<0.05).Compared with 21 d hypobaric hypoxia group,the mice in hypobaric hypoxia 21 d+MG132 group showed a higher new object recognition index(P<0.01).Conclusion The proteasome inhibitor MG132 could alleviate the memory impairment induced by chronic hypoxia in mice,and its mechanism may be related to the inhibition of Ub-K63 and Ub-K48,which in turn upregulates expression of TH in dopaminergic neurons.

Objective To observe the effect of Ginkgo biloba extract(GBE)on depression like behavior in post stroke depression(PSD)model rats,and explore the mechanism of regulating Toll like receptor 4/nuclear factor-κ B(TLR4/NF-κB)pathway to inhibit neuroinflammation.Methods Rats were randomly divided into 6 groups,sham,cerebral ischemia,PSD,paroxetine,low-dose Ginkgo biloba extract(GBE-L)and high-dose Ginkgo biloba extract(GBE-H)groups,10 rats in each group.Except for the sham group,middle cerebral artery occlusion(MCAO)was performed to prepare a left focal cerebral ischemia model.Except for the sham group and cerebral ischemia group,other groups were subjected to chronic unpredictable mild stress(CUMS)to establish PSD rat model for 8 weeks.After 4 weeks of CUMS,the paroxetine group,GBE-L,and GBE-H were treated with paroxetine 5 mg·kg-1,GBE 50 mg·kg-1,and GBE 100 mg·kg-1,respectively.The sham group,cerebral ischemia group,and PSD group were treated with the same volume of 0.9％NaCl and continuously administered by gavage for 28 d.After 4 weeks and 8 weeks of CUMS,the body weight and sugar preference test were measured.Levels of serum tumor necrosis factor-α(TNF-α),interleukin-1 β(IL-1 β)and levels of norepinephrine(NE),serotonin(5-HT),and dopamine(DA)in the cerebral cortex were measured by enzyme-linked immunosorbent assay(ELISA).The mRNA levels of Tlr4,Nfkb1,and nuclear factor κ B-kinase subunit β inhibitory factor(Ikbkb)in the hippocampus of rats were detected by polymerase chain reaction.The protein levels of NF-κB,nuclear factor κB inhibitory protein α(IKBα)and phosphorylation nuclear factor κB inhibitory protein α(p-IKB)in hippocampal tissue were detected by Western blot.Results The body weights of rats in the sham group,cerebral ischemia group,PSD group,paroxetine group,GBE-L group and GBE-H group were(427.10±6.36),(403.10±7.37),(310.10±9.71),(355.00±4.03),(347.90±9.88)and(391.90±5.07)g;sugar preference rate were(93.93±1.78)％,(91.57±1.03)％,(54.72±7.34)％,(88.35±4.36)％,(63.55±12.73)％and(81.04±4.31)％;the levels of NE in the cerebral cortex were(1 951.14±52.86),(1 827.27±23.63),(1 662.12±35.92),(2 033.58±72.28),(1 887.31±33.07)and(2 175.00±42.54)pg·mL-1;the levels of 5-HT in the cerebral cortex were(237.07±8.86),(226.15±10.27),(214.51±3.46),(297.13±5.79),(274.14±7.63)and(285.34±8.72)ng·mL-1;the levels of DA in the cerebral cortex were(1 531.11±47.26),(1 209.89±58.09),(1 143.15±36.31),(1 812.67±51.28),(1 651.56±31.82)and(1 853.33±20.42)pg·mL-1.Compared with the PSD group,GBE significantly increased the body weight of rats(P＜0.01)and increased the preference rate of sugar water in rats,showing the antidepressant like behavioral.GBE significantly reduced the levels of serum TNF-α,IL-1 β(all P＜0.01),increased the levels of NE,5-HT,and DA in the cerebral cortex(all P＜0.01),down regulate the mRNA levels of Tlr4,Nfkb1 and Ikbkb(P＜0.05,P＜0.01),reduced the expression of NF-κB(P＜0.01),and reduced the phosphorylation of IKBα(P＜0.01).Conclusion Ginkgo biloba extract can improve depression-like behavior in PSD model rats,and has antidepressant effect.Its mechanism is related to the inhibition of TLR4/NF-κB pathway,thus reducing neuroinflammation.

Objective To construct the demand model of four types of medical resources including beds in hospi-tal,beds in intensive care unit(ICU),ventilators and medical human resources during the major infectious disease epidemic events,simulate and analyze the treatment of infectious diseases when different medical resources are in short supply.Methods Based on the susceptible-exposed-infectious-recovered(SEIR)model,considering the infec-tivity of infected persons,the susceptibility of the population and the immunity of convalescents,the characteristics of asymptomatic COVID-19 patients and different clinical types,the"COVID-19 infection-hospitalization model"was constructed.By collecting and setting the parameters of disease transmission,clinical course and medical re-source shortage scenarios,an analysis model of allocation and supply of urban medical resources during infectious di-sease epidemic events was initially formed based on Anylogic platform,the supply and demand of medical resources during infectious disease events in different scenarios were analyzed.Results In the non-intervention scenario,the peak time of bed demand was on the 107th day,and the peak value was 160.92 beds per thousand people;the peak time of ventilator demand was on the 122nd day,and the peak value was 5.61 units per thousand people;the peak time of ICU bed demand was on the 117th day,and the peak value was 12.78 beds per thousand people;the peak time of the demand for medical human resources was on the 109th day,and the peak value was 151.12 persons per thousand persons.The simulation results suggested that there were some differences in the impact of different medi-cal resources on the outcome of medical treatment.Conclusion This study constructs an analytical tool for the allo-cation and supply of urban medical resources under the epidemic events of infectious diseases,and the results of mul-tiple simulation experiments suggest that bed resources and medical human resources play more important roles in the outcome of medical treatment.

OBJECTIVE: To investigate the safety and efficacy of reinforced radiculoplasty in the treatment of symptomatic sacral Tarlov cysts (TCs). METHODS: A retrospective analysis was performed on the clinical data and follow-up data of 71 patients with symptomatic sacral TCs who underwent reinforced radiculoplasty in the Neurosurgery Department of Peking University Third Hospital from June 2018 to March 2021. All the operations were performed under neuroelectrophysiological monitoring. Intraoperative cyst exploration, partial resection of the cyst wall, narrowing of the leak, nerve root sleeve radiculoplasty and artificial dural reinforcement were performed. The incidence of postoperative complications and new neurological dysfunction was analyzed. Visual analogue scale (VAS) was used to assess the changes of pain before and after surgery. The Japanese Orthopedics Association (JOA) low back pain score was used to evaluate the changes in nerve function before and after surgery. RESULTS: In the study, 71 patients had 101 TCs, 19 (18.8%) TCs originated from the left S1 nerve, 26 (25.7%) originated from the left S2 nerve, 3 (3.0%) originated from the left S3 nerve, 14 (13.9%) originated from the right S1 nerve, 33 (32.7%) originated from the right S2 nerve, 6 (5.9%) originated from the right S3 nerve, all the TCs underwent reinforced radiculoplasty. Deep infection (1 case), subcutaneous effusion (1 case), fat li-quefaction (1 case) and urinary tract infection (4 cases) were recorded postoperatively. The patients were followed up for 12-43 months (median, 26 months). Two cases had new urinary retention after operation, and the catheter was removed at the end of the first and second months respectively. One case had new fecal weakness, which improved after 3 months. Compared with preoperation, VAS decreased significantly at the last follow-up [median, 6 (4-9) vs. 1 (0-5), Z=-7.272, P < 0.001], JOA score increased significantly [median, 20 (16-25) vs. 27 (18-29), Z=-7.265, P < 0.001]. There were 18 cured cases (25.4%), 41 excellent cases (57.7%), 8 effective cases (11.3%), and 4 invalid cases (5.6%). The total efficiency was 94.4% (67/71). Two (1.98%) cysts recurred. CONCLUSION For patients with symptomatic sacral TCs, reinforced radiculoplasty can significantly improve the pain and nerve function, which is safe and reliable.
Humans ; Tarlov Cysts/epidemiology* ; Retrospective Studies ; Neoplasm Recurrence, Local/complications* ; Cysts/surgery* ; Pain

Objective:To investigate the expression of adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation in corneal epithelial cells and the effects of fungus on AMPK phosphorylation and interleukin-6 (IL-6) production in corneal epithelial cells.Methods:The human immortalized corneal epithelial cell line was selected.The safe concentration range of AMPK agonist 5-aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR) (100, 300, 500, 1 000 μmol/L) and inhibitor Compound C (10.0, 12.5, 15.0, 17.5, 20.0 μmol/L) on corneal epithelial cells was screened by multi-function real-time unlabeled cell analyzer.Corneal epithelial cells without any treatment were used as the normal control group, and those co-cultured with spores were used as the spore control group.Corneal epithelial cells co-cultured with spores were treated with AICAR and Compound C for 4 hours in the AICAR group and Compound C group, respectively.The expression of phosphorylated AMPK (p-AMPK) and AMPK in corneal epithelial cells was detected by Western blot, and the concentration of IL-6 in the culture supernatant was determined by enzyme-linked immunosorbent assay (ELISA).Results:After treatment with different concentrations of AICAR for different periods, there was no statistical significance in the cell index of corneal epithelial cells (all at P>0.05). The cell index of corneal epithelial cells was increased with 10.0 μmol/L and 12.5 μmol/L Compound C treatment compared with that of the normal control group.The expression levels of p-AMPK were 0.67±0.15, 2.57±0.12, 3.67±0.58 and 1.50±0.50, respectively, in the normal control group, spore control group, AICAR group and Compound C group, showing a statistically significant difference among them ( F=32.820, P<0.001). The expression level of p-AMPK was significantly higher in the spore control group compared with the normal control group ( P<0.001). The expression level of p-AMPK in the AICAR group was higher than that in the spore control group, and the expression level of p-AMPK in the Compound C group was lower than that in the spore control group, and the differences were statistically significant (both at P=0.010). There was no significant difference in the relative expression level of AMPK among the four groups ( F=0.120, P=0.950). The expression levels of IL-6 concentration in the normal control group, spore control group, AICAR group and Compound C group were (107.81±17.15), (156.32±9.94), (167.96±14.16) and (127.42±19.75)pg/ml, respectively, showing a statistically significant difference among them ( F=15.210, P<0.001). The IL-6 concentration of the spore control group was higher than that of the normal control group, and the difference was statistically significant ( P<0.001). The IL-6 concentration of the AICAR group was higher than that of the spore control group, but the difference was not statistically significant ( P=0.260). The IL-6 concentration of the Compound C group was lower than that of the spore control group, and the difference was statistically significant ( P=0.010). Conclusions:In corneal epithelial cells, AMPK phosphorylation is found, which is enhanced after fungal spores stimulation, and the secretion of IL-6 increases.

Objective: To estimate the incidence of HIV-1 infection in men who have sex with men (MSM) in key areas of China through HIV-1 limiting antigen avidity enzyme immunoassay (LAg-Avidity EIA), analyze the deviation from the actual results and identify influencing factors, and provided reference for improving the accuracy of estimation results. Methods: Based on the principle of the cohort randomized study design, 20 cities were selected in China based on population size and the number of HIV-positive MSM. The sample size was estimated to be 700 according to the HIV-1 infection rate in MSM. MSM mobile phone app. was used to establish a detection appointment and questionnaire system, and the baseline cross-sectional survey was conducted from April to November 2019. LAg-Avidity EIA was used to identify the recent infected samples. The incidence of HIV-1 infection was calculated and then adjusted based on the estimation formula designed by WHO. The influencing factors were identified by analyzing the sample collection and detection processes. Results: Among the 10 650 blood samples from the participants, 799 were HIV-positive in initial screening, in which 198 samples (24.78%) missed during confirmation test. Only 621 samples were received by the laboratory. After excluding misreported samples, 520 samples were qualified for testing. A total of 155 samples were eventually determined as recent infection through LAg-Avidity EIA; Based on the estimation formula , the incidence of HIV-1 infection in MSM in 20 cities was 4.06% (95%CI:3.27%-4.85%), it increased to 5.53% (95%CI: 4.45%-6.60%)after the adjusting for sample missing rate. When the sample missing rate and misreporting rate were both adjusted, the incidence of HIV-1 infection in the MSM increased to 5.66% (95%CI:4.67%-6.65%). The actual incidence of HIV-1 infection in MSM in the 20 cities might be between 4.06% and 5.66%. Conclusions: Sample missing and misreporting might cause the deviation of the estimation of HIV-1 infection incidence. It is important to ensure the sample source and the quality of sample collection and detection to reduce the deviation in the estimation of HIV-1 infection incidence.
Cross-Sectional Studies ; HIV Infections/epidemiology* ; HIV-1 ; Homosexuality, Male ; Humans ; Immunoenzyme Techniques ; Incidence ; Male ; Sexual and Gender Minorities

OBJECTIVE: To analyze characteristics and related factors of the plantar pressure during the level walking and single leg standing in the chronic ankle instability (CAI) individuals. METHODS: From April 2019, 75 CAI individuals and 40 healthy individuals were enrolled in this study. Both of the static and dynamic plantar pressure were measured during six times level walking and three times single leg standing testing. The data including peak force, time to peak force in various foot contact areas and the time to boundary (TTB) and velocity of center of pressure (COP) were measured and compared between the affected side and the unaffected side and between the CAI cases and the healthy individuals. The correlations between the plantar pressure and the gender, Beighton score, affected side and body mass index (BMI) were analyzed. RESULTS: The characteristics of plantar pressure distribution in the CAI individuals included: (1) During the level walking, the affected side showed the similar pressure contribution as the unaffected side (P>0.05). While compared with healthy individuals, there was a significantly higher peak force in the 5th metatarsal area (t=-3.86, P=0.03) of the affected side, lower peak force in the 1st (t=2.99, P=0.02), 2nd metatarsal head areas (t=2.09, P=0.01) of the affected side, medial hindfoot areas of both sides (affected, t=2.33, P=0.01; unaffected, t=3.74, P=0.02) and toes areass of both sides (affected, t=2.23, P=0.01; unaffected, t=3.28, P=0.02) and a delay to peak force in the 4th metatarsal head area (t=3.33, P=0.01) of the affected side. (2) During the single leg standing, the CAI individuals showed significantly worse balance control in the anterior/posterior direction (P < 0.05) and lateral/medial direction (P < 0.05) compared with the healthy controls, and the affected side had more severe balance control deficit in the lateral/medial direction (P < 0.05). (3) The women (P < 0.05) and the individuals with higher Beighton scores (P < 0.05) showed worse balance control deficit in the lateral/medial direction. CONCLUSION CAI individuals showed significantly a more lateral shifted plantar distribution during the level walking compared with the healthy individuals and the tendency was worse on the affected sides, and showed worse balance control in the anterior/posterior direction and lateral/medial direction during the single leg standing. The women and those with generalized ligament laxity showed significantly worse balance control.
Ankle ; Ankle Joint ; Case-Control Studies ; Female ; Foot ; Humans ; Joint Instability

Porcine epidemic diarrhea (PED) is a major disease of pigs that inflicts heavy losses on the global pig industry. The etiologic agent is the porcine epidemic diarrhea virus (PEDV), which is assigned to the genus Alphacoronavirus in the family Coronaviridae. This review consists of five parts, the first of which provides a brief introduction to PEDV and its epidemiology. Part two outlines the passive immunity in new born piglets and the important role of colostrum, while the third part summarizes the characteristics of the immune systems of pregnant sows, discusses the concept of the "gut-mammary gland-secretory IgA(sIgA) axis" and the possible underpinning mechanisms, and proposes issues to be addressed when designing a PEDV live vaccine. The final two parts summarizes the advances in the R&D of PEDV vaccines and prospects future perspectives on prevention and control of PEDV, respectively.
Animals ; Antibodies, Viral ; Coronavirus Infections/veterinary* ; Female ; Immunization ; Porcine epidemic diarrhea virus ; Pregnancy ; Swine ; Swine Diseases/prevention & control* ; Viral Vaccines