Influenza virus causes serious threat to human life and health. Due to the inherent high variability of influenza virus, clinically resistant mutant strains of currently approved anti-influenza virus drugs have emerged. Therefore, it is urgent to develop antiviral drugs with new targets or mechanisms of action. RNA-dependent RNA polymerase is directly responsible for viral RNA transcription and replication, and plays key roles in the viral life cycle, which is considered an important target of anti-influenza drug design. From the point of view of medicinal chemistry, this review summarizes current advances in diverse small-molecule inhibitors targeting influenza virus RNA-dependent RNA polymerase, hoping to provide valuable reference for development of novel antiviral drugs.

Objective To explore whether the cognitive function of central obese mice is decreased by affecting the expression of brain-derived neurotrophic factor(BDNF)in hippocampus.Methods Healthy mice at the neonatal stage were divided into normal group and model group at random.To obtain the obese models,model group mice were injected at cervical subcutaneous with 10％L-monosodium glutamate(MSG;3 mg·g-1·d-1)for 5 days.The normal group was injected with the same dose of 0.9％NaCl.In addition,mice were removed according to the requirements.Finally,we got 8 mice in each group.The following parameters were compared:body weight,Lee's index and levels of the serum lipid.The BDNF expression levels in hippocampal tissue were measured using western blotting.Results At the 8th weekend,the body weight of the model and normal groups was(49.01±2.47)and(41.27±3.28)g;the Lee's indexes were(357.14±9.24)and(330.15±7.37)g1/3·cm-1;triglyceride levels were(1.37±0.52)and(0.73±0.31)mmol·L-1;total cholesterol levels were(2.98±0.18)and(1.98±0.30)mmol·L-1;low-density lipoprotein levels were(0.31±0.03)and(0.24±0.02)mmol·L-1;high-density lipoprotein levels were(2.70±0.15)and(1.98±0.40)mmol·L-1;the differences were statistically significant(P＜0.05,P＜0.01),which were consistent with the characteristics of the central obesity model.The BDNF protein expression levels in the hippocampus of the model and normal groups were 6.02 x 104±626.53 and 7.04 x 104±1 440.81,which has statistically significant(P＜0.01).Conclusion The cognitive function of central obese mice may be decreased by down-regulating the expression of BDNF in hippocampus.

Objective To summarize the experience and practical value of living donor kidney harvesting in Bama miniature pigs with six gene modified. Methods The left kidney of Bama miniature pigs with six gene modified was obtained by living donor kidney harvesting technique. First, the ureter was occluded, and then the inferior vena cava and abdominal aorta were freed. During the harvesting process, the ureter, renal vein and renal artery were exposed and freed in sequence. The vascular forceps were used at the abdominal aorta and inferior vena cava, and the renal artery and vein were immediately perfused with 4℃ renal preservation solution, and stored in ice normal saline for subsequent transplantation. Simultaneously, the donor abdominal aorta and inferior vena cava gap were sutured. The operation time, blood loss, warm and cold ischemia time, postoperative complications and the survival of donors and recipients were recorded. Results The left kidney of the genetically modified pig was successfully harvested. Intraoperative bleeding was 5 mL, warm ischemia time was 45 s, and cold ischemia time was 2.5 h. Neither donor nor recipient pig received blood transfusion, and urinary function of the kidney transplanted into the recipient was recovered. The donor survived for more than 8 months after the left kidney was resected. Conclusions Living donor kidney harvesting is safe and reliable in genetically modified pigs. Branch blood vessels could be processed during kidney harvesting, which shortens the process of kidney repair and the time of cold ischemia. Living donor kidney harvesting contributes to subsequent survival of donors and other scientific researches.

Objective In this study, a strain of colistin and tigecycline-resistant bacteria isolated in 2009 was analyzed, and the structure of drug-resistant plasmid and genetic environment were discussed, so as to provide basis for the prevention and control of multidrug-resistant bacteria. Methods A strain (GZ12244) with positive mcr and tet(M) was obtained by screening colistin and tigecycline resistance genes. Vitek-2 was used for strain identification, and the drug sensitivity test was carried out by broth dilution method. The molecular typing, drug resistance genes, insertion sequences, plasmid structure and genetic background were analyzed by genome-wide sequencing and bioinformatics. Results Strain GZ12244 is Klebsiella pneumoniae, which is resistant to colistin B, tigecycline, cefuroxime and tetracycline, and carries a variety of drug-resistant related genes such as mcr-1 and tet(M), and some of the drug-resistant genes with antibiotic efflux and antibiotic target change have amino acid substitution mutations. Mcr-1 and tet(M) coexist in a plasmid, and mcr-1 flanked by two insertion sequences ISApl1. There are insertion sequences such as IS15, IS1D and ISEc63 in the upstream and downstream of tet(M) gene. Conclusion Klebsiella pneumoniae GZ12244 is a multidrug-resistant strain. The drug-resistant gene exists in plasmid, and the mobile elements in upstream and downstream may spread the drug-resistant gene.

Objective To analyze the combined effect of body mass index(BMI)and age with cancer occurrence among a hypertensive population in Minhang District,Shanghai.Methods Participants of this study were 212 394 hypertensive patients without cancer in Minhang District,Shanghai,registered in the electronic health information system from 2007 to 2015.Age and BMI were included as smoothing functions in the generalized additive Cox proportional risk model.The bivariate response model was constructed to visualize results using surface plots and to comprehensively analyze the association of BMI and age with the risk of cancer occurrence.Results A total of 22 141 participants developed cancer by Dec 31,2018.The association between age and the risk of cancer incidence showed an overall linear trend while the association between BMI and the risk of cancer incidence showed an overall"U"shape.BMI at about 26 kg/m2 showed the lowest risk of cancer incidence.The risk of cancer occurrence increased with increasing age in people with different BMIs.The associations between BMI and the risk of cancer incidence were different at different age groups:there was no significant association between BMI and the risk of cancer incidence in the young people(20-44 years).While in the middle-aged and older people aged over 45 years,BMI was associated with the risk of cancer incidence in a"U"shape.The lowest risk of cancer incidence was around the BMI of 26 kg/m2.Conclusion BMI among the population with hypertension should be controlled in a reasonable range,especially in the middle-aged and older population,to prevent cancer occurrence.

A portable multi-wavelength spectral detector was developed for on-site,rapid and accurate detection of organic pollutants in surface water using ultraviolet light-emitting diodes(UV-LEDs)and the corresponding spectral detection method was built.By measuring the fluorescence spectrum and absorption light intensity and combining with the multi-wavelength spectral correlation calculation method to analyze the target,the developed detector was able to qualitatively and quantitatively detect organic pollutants that responded in the UV-light range of 260-370 nm.The proposed detector was used to detect polycyclic aromatic hydrocarbons(PAHs)and Rhodamine B.The linear ranges of anthracene and Rhodamine B in absorption mode were 10-100 and 8.5-100 mg/L,respectively.In fluorescence mode,the linear ranges for anthracene and Rhodamine B were 0.006-50 and 0.02-0.781 mg/L,correspondingly.The absorption/fluorescence concurrent mode could extend the detection ranges of anthracene and Rhodamine B to 0.006-100 and 0.02-100 mg/L,respectively.The recoveries of PAHs in surface water ranged from 97.4%to 105.1%for anthracene and 84.5%to 91.2%for anthracene,naphthalene,and pyrene in absorption and fluorescence modes,respectively.The method was accurate in both modes.The mixtures containing PAHs were identified by the proposed method under the optimized multi-wavelength spectral correlation calculation.The results demonstrated that the method could achieve a similarity of 75%or more when identifying two different concentrations of solutions containing a single or a mixture of targets within the linear concentration range of the targets.However,the similarity dropped to less than 25%when identifying two solutions of different substances.The proposed method had excellent recognition abilityof targets.The proposed detector and method combined fluorescence and absorption spectroscopy,which could expand the application of spectroscopy in the in situ rapid identification and detection of pollutants such as PAHs in surface water.

Objective To investigate the relationship between the changes of serum human surfactant pro-tein D(SP-D)and vascular cell adhesion molecule-1(sVCAM-1)levels and postoperative fracture healing and short-term prognosis in patients with traumatic rib fractures.Methods A total of 102 patients with traumatic rib fractures who were treated in Banan Hospital Affiliated to Chongqing Medical University from January 2020 to December 2021 were selected as the research objects.After 8 months of treatment,the healing status of the patients was analyzed and divided into non-healing group(21 cases)and healing group(81 cases).Ac-cording to the pulmonary contusion,the patients were divided into pulmonary contusion group(19 cases)and non-pulmonary contusion group(83 cases).The serum levels of SP-D and sVCAM-1 were compared between the healing group and the non-healing group,and between the pulmonary contusion group and the non-pulmo-nary contusion group.The relationship between the changes of serum SP-D and sVCAM-1 levels and postop-erative fracture healing and short-term prognosis in patients with traumatic rib fractures were studied.Results The levels of SP-D and sVCAM-1 in the healing group were lower than those in the non-healing group(P＜0.05).The levels of SP-D and sVCAM-1 in the non-pulmonary contusion group were lower than those in the pulmonary contusion group(P＜0.05).Serum SP-D and sVCAM-1 levels were independent risk factors for postoperative fracture healing and short-term prognosis.Conclusion The changes of serum SP-D and sVCAM-1 levels in patients with traumatic rib fractures are related to fracture healing and short-term prognosis,which can be used as an important reference for prognosis evaluation.

The current situation of childrearing in the elderly and low birth rate showed that the prevention and treatment of infertility risk caused by the decline of male reproductive function are increasingly becoming prominent.The decline of male reproductive function is closely related to the hypothalamic-pituitary-gonadal axis,oxygen free radicals,blood-testis barrier,and the apoptosis of spermatogenic cells.Traditional Chinese medicine believes that the kidney stores essence and is in charge of reproduction,and the decline of reproductive function is closely related to the imbalance of yin and yang of the kidney.Therefore,kidney-supplementing method is helpful for treating the decline of reproductive function caused by kidney deficiency.Kidney-supplementing prescriptions were effective on systematically regulating the function of the hypothalamic-pituitary-gonadal axis,thus to significantly delay the decline of reproductive function,were effective on removing excessive oxygen free radicals in the body and protecting cells from oxidative damage,and were effective on improving spermatogenesis by restoring the blood-testis barrier and regulating the apoptosis of spermatogenic cells.The representative kidney-supplementing prescriptions for improving the decline of reproductive function caused by kidney deficiency include Wuzi Yanzong Pills,Shenqi Pills,Yougui Pills,Liuwei Dihuang Pills,Zuogui Pills and Guilu Erxian Soft Extract.The above formulas presented no single therapeutic mechanism but multiple-way,multiple-level and multiple-target mechanism,and the formulas can comprehensively regulate the internal environment of the body,so as to achieve the purpose of improving male reproductive function.The kidney-supplementing therapy of traditional Chinese medicine plays an irreplaceable role in the treatment of male reproductive function decline.The in-depth study of its therapeutic mechanism will provide guide for clinical practice and will supply theoretical basis for improving male reproductive function decline.

Objective To design a small-size dual-microphone front-end system to solve the problems of the portable field medical equipment in speech interaction due to noises in field conditions.Methods The system realized small-size dual-microphone beamforming based on the least squares criterion and then implemented front-end speech enhancement,which was composed of dual microphones(SMD micro electro mechanical system microphone),a signal preprocessing module,an embedded processor(STM32F405 series processor),an analog to digital converter(ADC),an digital to analog converter(DAC)and a power supply module.The signal preprocessing module,ADC and DAC were built into the general-purpose audio encoder WM8978,and a LM1117 voltage regulator chip was adopted as the power supply module.Keil μ Vision4 development software was used for software compiling and testing.Directivity experiment and speech enhancement experiment were carried out to verify the performance of the system.Results Directivity experiment showed that the system gained high directivity consistency at each frequency point in the frequency range of 0.5 to 2.0 kHz;speech enhancement experiment indicated that the system effectively improved the sound quality and recognition rate of speech under the conditions of three types of non-smooth noises,namely,gunshot,alarm of the monitor and collision of the medical utensils.Connclusion The system developed can realize speech enhancement to facilitate speech interaction of the portable field medical equipment.[Chinese Medical Equipment Journal,2024,45(11):39-43]

Objective To explore the muscle force characteristics of the knee joint during a Taekwondo roundhouse kick in Korea.Methods Kinematic and dynamic data from twelve elite Taekwondo athletes were collected using the DaeDo electronic scoring system,Vicon optical motion capture system,Kistler three-dimensional force plates.The OpenSim software was used to simulate these movements and calculate the muscle forces,joint torques,joint stiffness,and muscle coordination patterns of the knee.Results During the knee-lifting and striking phases,the coronal torque of the knee joint in the attacking leg was significant,and the sagittal torque peaked during the strike.For the supporting leg,the highest coronal torque of the knee joint occurred during knee lifting,with the sagittal torque reaching its peak during strike.In terms of muscle activity,the semimembranosus and long head of the biceps femoris in the attacking leg exerted greater force during the striking phase,whereas the semimembranosus and medial head of the gastrocnemius in the supporting leg were more active during the recovery phase.Five muscle synergy patterns were observed during the Taekwondo roundhouse kick.Conclusions Significant differences were found in the muscle forces and knee joint torques of the attacking and supporting legs when athletes performed the roundhouse kick,and there was a complex muscle synergy.