Analysis of cases of reinfection of past SARS-CoV-2 patients in Pudong New Area of Shanghai / 上海预防医学

ObjectiveTo identify the rate， population characteristics， and vaccination history of repeat infections among previously infected people in the current epidemic based on the rate of repeat infection and population characteristics of different mutant strains at different times in Pudong New Area of Shanghai， and to provide reference for the prevention and control strategies of novel coronavirus repeat infections. MethodsA total of 9 250 investigated subjects were randomly selected from the new cases of asymptomatic infection and confirmed cases reported by Pudong New Area from March to May 2022. The investigation mainly focused on demographic characteristics， nucleic acid or antigen test results， and symptoms after infection. The repeat infection rates among different populations were compared， and logistic regression was used to analyze the impact of gender， age， and vaccination status on repeat infections. ResultsThe survey sample of 9 250 people had a response rate of 81.85%. There were 4 043 males （53.40%） and 3 528 females （46.60%）， with a median age of 34 years old （P25， P75： 7， 61）. The overall vaccine uptake rate was 59.44% （4 500/7 571）. In December of 2022， there were 563 cases of repeat infection， with an infection rate of 7.44%. The lowest rate of repeat infection was seen in the 3‒ year-old group （2.86%） and the highest rate in the 30‒ year-old group （12.42%）， with significant differences between different age groups. The repeated infection rate for those who had completed their vaccinations was significantly lower （6.57%） compared to those who had not （7.11%）. The age groups of 3‒ years， 70‒79 years， as well as individuals who completed full vaccination and received booster shots were protective factors against repeat infections. ConclusionThe overall rate of reinfection among the infected in Shanghai during the spring of 2022 was low in the outbreak of the Omicron variant， and the rate of reinfection in the 3‒ year-old group was significantly lower than in other age groups. Completing the full course of vaccination significantly reduces the risk of reinfection. Although the reinfection rate is high in individuals who received booster shots， it remains a mitigating factor compared to those who do not receive the vaccine. It is recommended to continue monitoring reinfections in key populations and further strengthen immunization efforts.

Acupotomy ameliorates subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis by regulating bone morphogenetic protein 2-Smad1 pathway.

OBJECTIVE: To investigate the effects of acupotomy on the subchondral bone absorption and mechanical properties in rabbits with knee osteoarthritis (KOA). METHODS: The rabbits were divided into blank control, model, acupotomy and electroacupuncture (EA) groups, with 12 rabbits in each. Modified Videman's method was used to prepare KOA model. The acupotomy and EA group were given indicated intervention for 3 weeks. The behavior of rabbits in each group was recorded. Subsequently, cartilage-subchondral bone units were obtained and morphological changes were observed by optical microscope and micro computed tomography. Compression test was used to detect the mechanical properties of subchondral bone, Western blot and real-time polymerase chain reaction (RT-PCR) were applied to detect the expression of bone morphogenetic protein 2-Smad1 (BMP2-Smad1) pathway in subchondral bone. RESULTS: Compared with the control group, rabbits in the KOA group showed lameness, knee pain, and cartilage degradation; the subchondral bone showed active resorption, the mechanical properties decreased significantly and the BMP2-Smad1 pathway downregulated significantly. Both acupotomy and EA intervention could increase the thickness of trabecular bone (Tb. Th), the bone volume fraction (BV/TV) and the thickness of subchondral bone plate, reduce the separation of trabecular bone (Tb. Sp), improve the maximum load and elastic modulus of subchondral bone, and effectively delay cartilage degeneration in KOA rabbits. This process may be achieved through upregulation the related proteins of BMP2-Smad1 pathway. The maximum load and elastic modulus of subchondral bone in the acupotomy group were slightly better than those in the EA group. CONCLUSIONS: Acupotomy could effectively protect cartilage by inhibiting abnormal bone resorption and improving mechanical properties of subchondral bone thorough the related proteins of BMP2-Smad1 pathway in KOA rabbits.

Analysis of Effect of Characteristic Processing with Rice-washed Water on Volatile Components in Raw and Bran-fried Products of Atractylodis Macrocephalae Rhizoma by HS-GC-MS / 中国实验方剂学杂志

ObjectiveBy comparing the differences in composition and content of volatile components between Atractylodis Macrocephalae Rhizoma（AMR）and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， the effect of processing with rice-washed water on the volatile components in AMR and bran-fried AMR were investigated. MethodHeadspace gas chromatography-mass spectrometry（HS-GC-MS）was used to determine the volatile components in raw products， bran-fried products and their processed products with rice-washed water. GC conditions were programmed temperature（starting temperature of 50 ℃， rising to 140 ℃ at 10 ℃·min-1， maintained for 5 min， then rising to 210 ℃ at 4 ℃·min-1）， splitting ratio of 10∶1， high purity helium as the carrier gas and a solvent delay time of 3 min. MS conditions were an electron bombardment ion source（EI） with an electron collision energy of 70 eV， ion source temperature of 230 ℃， and the detection range of m/z 20-650. The relative contents of the components were determined by the peak area normalization method， the obtained sample data were subjected to principal component analysis（PCA） and orthogonal partial least squares-discriminant analysis（OPLS-DA） by SIMCA 14.1 software， and the differential components of AMR and bleaching AMR， and bran-fried AMR and bran-fried bleaching AMR were screened according to variable importance in the projection（VIP） value>1 and P<0.05. ResultA total of 71 volatile components were identified， including 53 in AMR， 50 in bleaching AMR， 51 in bran-fried AMR， and 44 in bran-fried bleaching AMR. OPLS-DA results showed that there were significant differences between AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， but not between AMR samples from different origins. The compound composition of AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR did not change， but the contents of monoterpenes and sesquiterpenes changed significantly. ConclusionSignificant changes in the contents of volatile components were observed in AMR and bleaching AMR， bran-fried AMR and bran-fried bleaching AMR， among them， 1，2-dimethyl-4-methylidenecyclopentene， 9，10-dehydro-isolongifolene， γ-elemene， zingiberene， atractylone， silphinene， modhephene and （1S，4S，4aS）-1-isopropyl-4，7-dimethyl-1，2，3，4，4a，5-hexahydronaphthalene can be used as candidate differential markers of volatile components of AMR before and after processing with rice-washed water.

Epidemiological and clinical features of the 2019 novel coronavirus outbreak in China

Our manuscript was based on surveillance cases of COVID-19 identified before January 26, 2020. As of February 20, 2020, the total number of confirmed cases in mainland China has reached 18 times of the number in our manuscript. While the methods and the main conclusions in our original analyses remain solid, we decided to withdraw this preprint for the time being, and will replace it with a more up-to-date version shortly. Should you have any comments or suggestions, please feel free to contact the corresponding author.

A analysis of the risk factors of colorectal polyp malignant transformation / 重庆医学

Objective Colorectal polyp is a precancerous lesion of colorectal cancer .Aim of the study was to explore the risk fac-tors of colorectal polyp malignant transformation .Methods The related information of 75 084 colonoscopies performed from 2003 to 2012 in Southwest Hospital in Chongqing were collected and the relationship between polyp malignant transformation and the pa-tient age ,sex ,polyp location ,size or histological types was analyzed .Results From 2003 to 2012 ,polyps were diagnosed in 14 806 cases of the total 75 084 patients with a 19 .72% detection rate .There were significant difference of the left-side and right-side pol-yp detection rate in different age groups ,and the frequency of polyps distributed in the whole colorectum increased with the increase of age .The rates of epithelial neoplasia and malignant transformation increased with age .At the same time ,malignant transforma-tion rate was significant higher in polyps located in left-side than that in right-side (P<0 .0167) ,in adenoma than that in inflamma-tory hyperplastic polyp (P<0 .01) .The larger diameter and the more villus ,the higher rate of malignant transformation .Conclusion Patient age ,polyp size ,location and histological type could be considered as the significant predictors of colorectal polyp malignant transformation .It may be useful to treat the polyp with endoscopy in patient with age more than 45 and adenoma whose diameter was not less than 1 cm ,located in left-side for prevention of colorectal cancer .