[Application and research progress of patient-derived organoids in the multimodality treatment of pancreatic cancer].

Pancreatic cancer is one of the most malignant tumors with a 5-year survival rate of 13%. Difficulty in early diagnosis,high tumor heterogeneity,high rate of drug resistance,and lack of effective new drugs are the main reasons for the poor therapeutic effect. Traditional cell line models cannot simulate the tumor environment in vitro and cannot reflect the heterogeneity of pancreatic cancer,while animal models have a long culture process and cannot be used for high-throughput screening. Pancreatic cancer organoids can be continuously expanded and cultured in vitro,which can realistically reflect the heterogeneity of pancreatic cancer and allow high-throughput drug screening,making it an ideal tool for individualized precision diagnosis and treatment of pancreatic cancer. According to recent studies on the evaluation of clinical drug efficacy using pancreatic cancer organoids,the drug sensitivity of pancreatic cancer organoids is highly consistent with the clinical efficacy,demonstrating the feasibility of drug sensitivity of pancreatic cancer organoids in guiding clinical therapy,comfirming the ability to discover potential therapeutic drugs through high-throughput drug screening of pancreatic cancer organoids. At the same time,this review reveals the importance of pancreatic cancer organoids as a model of the pancreatic cancer microenvironment for the development of new drugs and tumor microenvironment research. and the role of pancreatic cancer organoids as a model that can reflect the specific microenvironment of pancreatic cancer for new drug discovery and microenvironmental evaluation. Pancreatic cancer organoids and organ-on-chips are powerful tools for precision companion therapy and new drug discovery.

[The association of cholesterol crystals and non-culprit plaque characteristics in AMI patients: an OCT study].

Objective: To analyze plaque characteristics of non-culprit coronary lesions with cholesterol crystals in patients with acute myocardial infarction(AMI) by using optical coherence tomography(OCT). We also investigated the potential association between cholesterol crystals with plaque rupture and healed plaque at non-culprit segment. Methods: This study was a retrospective cohort study. Between January 2017 and December 2017, patients with AMI who underwent 3-vessel OCT imaging were included in this study. Patients were divided into two groups according to the presence or absence of cholesterol crystals at the non-culprit lesions. All patients underwent coronary angiography and OCT examination, and non-culprit plaque characteristics were compared between the two groups. The generalized estimating equation log-binomial multirariate regression model was used to assess the relationship between non-culprit lesions with cholesterol crystals and plaque rupture and plaque healing. The follow-up data collection ended in October 2023. Kaplan-Meier survival curves were plotted, and log-rank tests were used to compare the cumulative incidence of major adverse cardiovascular events between the two groups. Results: A total of 173 AMI patients were included (aged (56.8±11.6) years; 124 men (71.7%)). Among 710 non-culprit lesions identified by OCT, there were 102 (14.4%) in cholesterol crystals group and 608 (85.6%) in non-cholesterol crystals group. Compared with non-culprit lesions without cholesterol crystals, those with cholesterol crystals had smaller minimum lumen diameter, severer diameter stenosis, and longer lesion length (all P<0.01). The prevalence of plaque rupture (17.6% (18/102) vs. 4.9% (30/608), P=0.001) and thin-cap fibroatheroma (31.4% (32/102) vs. 11.5% (70/608), P<0.01) was higher in the cholesterol crystals groups than in the non-cholesterol crystals group. In addition, vulnerable plaque characteristics such as (44.1% (45/102) vs. 25.8% (157/608), P<0.01), macrophages were more frequently observed in non-culprit lesions with cholesterol crystals. The generalized estimating equation log-binomial multivariate regression analyses showed that non-culprit cholesterol crystals were positively correlated with healed plaque (OR=1.583, 95%CI: 1.004-2.495, P=0.048). Conversely, cholesterol crystals were not associated with plaque rupture (OR=1.632, 95%CI: 0.745-3.576, P=0.221). The follow-up time was 2 142 (1 880, 2 198) days. Non-culprit cholesterol crystals were not related to the major adverse cardiovascular events in patients with AMI (log-rank P=0.558). Conclusions: Among AMI patients, non-culprit lesions with cholesterol crystals presented with severer luminal stenosis and increased plaque vulnerability. The presence of non-culprit cholesterol crystals was associated with rather than plaque rupture.

[Phenotype and genetic mutation analysis of an inherited protein C deficiency pedigree].

Objective: A phenotypic and gene mutation study was carried out to investigate the molecular mechanism of inherited protein C deficiency in a family with the disorder. Methods: The proband was a 21-year-old male who was admitted to hospital due to swelling of the left lower limb for 3 months and hemoptysis with chest tightness for more than 1 week. The clinical diagnosis was pulmonary embolism and deep vein thrombosis of the left lower limb. Plasma protein C activity, protein S activity and antithrombin Ⅲ activity were detected in the patient and their family members. Whole exon sequencing was used to analyze a total of 199 genes associated with thrombus susceptibility of the patient. After the mutation was found and Sanger sequencing was used to verify whether the family members carried the same gene mutations as the patient. The conservation of amino acid mutation sites was analyzed by using the software ClustalX-2.1-win. The damage of mutations to protein function was analyzed by PROVEAN and PolyPhen-2 online bioinformatics software. Finally, PyMOL 2.3 software was used to analyze the protein model. Results: The patient and four family members all had the identical heterozygous missense mutation c.1019 C>T (p. Thr340Met) in exon 9 of the protein C gene, resulting in various degrees of protein C deficiency. The Thr340 amino acid was discovered to be poorly conserved in seven homologous species after investigation with the clustalx-2.1-win software. P. Thr340Met was found to be a detrimental mutation by both PROVEAN and PolyPhen-2 online bioinformatics program. The mutation of Thr340 to Met340 caused the hydrogen bond between Thr340 and Gln226 to dissolve, changing the spatial arrangement of protein C, which might be the main explanation for the lower protein C activity, according to the protein model. Conclusions: Protein C deficiency in this family was caused by a hybrid missense mutation C. 1019 C>T (p. Thr340Met). Protein C deficiency may present in varying severity among mutation carriers at the same locus of the protein C gene. Whole-exome sequencing may be considered in young patients with spontaneous venous thromboembolism, even if there is no relevant family history.

[Correlative factors analysis and predictive model construction of intestinal flora imbalance during acute exacerbation of chronic obstructive pulmonary disease].

Objective: To explore correlative factors and construct predictive model of intestinal flora imbalance in patients with acute exacerbation of Chronic Obstructive Pulmonary Disease (COPD). Methods: The patients in acute exacerbation stage of COPD (AECOPD) hospitalized in Yixing People's Hospital from January 1 to December 31, 2019 were included. According to the clinical symptoms and results of fecal examination, the subjects were divided into case group (n=45) and control group (n=83). Multivariate logistic regression was used to analyze the correlative factors of intestinal flora imbalance in AECOPD patients. The prediction model of intestinal flora imbalance in patients with AECOPD was constructed according to the results of factor logistic regression analysis, and the effectiveness of the prediction model was evaluated by receiver operating characteristic (ROC) curve analysis. Results: The ages of subjects in case group and control group were (76±9) and (74±8) years old, respectively, among which males accounted for 80.0% (36/45) and 69.9% (58/83), respectively. The multivariate logistic regression model analysis showed that serum albumin concentration, frequency of acute exacerbation ≥2 times/year, complicated with chronic cor pulmonale and diabetes mellitus were correlative factors of intestinal flora imbalance in patients with AECOPD. The OR (95%CI) were 0.98 (0.80-0.97), 3.70 (1.79-11.72), 2.62 (1.46-10.80) and 3.85 (1.17-8.58), respectively. The prediction model of intestinal flora imbalance was logit P=3.858-0.13×serum albumin consentration+1.52×acute exacerbation ≥2 times/year+1.379×chronic cor pulmonale+1.155×diabetes mellitus. The area under the ROC curve of this model was 0.847 and the sensitivity and specificity of the prediction model were 88.9% and 71.1%, respectively. Conclusions: Serum albumin, frequency of acute exacerbation ≥2 times/year, complicated with chronic cor pulmonale and diabetes mellitus are correlative factors of intestinal flora imbalance in patients with AECOPD. The predictive model shows high clinical value in predicting intestinal flora imbalance in patients with AECOPD.

Significance of detecting IgH and TCRγ gene rearrangements in patients with hemopoietic maligancies by real-time quantitative PCR.

The aim of our study was to investigate the association of IgH and TCRγ gene rearrangements in hematological malignancies with the disease and clinical application. IgH and TCRγ gene rearrangements were determined in 69 paraffin and bone marrow specimens with SYBR Green I fluorescent dye and RQ-PCR method, including 21 paraffin-embedded tissues of the onset cases and 48 bone marrow samples, representing 15 ALL and 25 AML cases. After chemotherapy, 8 cases were NHL; the 10 cases of the negative control group were healthy people. Among the ALL cases, the IgH rearrangement occurred in 80.0%, the TCRγ rearrangement in 46.7%, and both gene rearrangements in 46.7%. Among the AML cases, the IgH rearrangement occurred in 72.0%, the TCRγ rearrangement in 68.0%, and both gene rearrangements in 60.0%. In the lymphoma cases, the IgH rearrangement occurred in 93.1%, the TCRγ rearrangement in 51.7%, and both gene rearrangements in 44.8%. In the negative control group, the 10 cases were all negative. There was the phenomenon of "sequence-non-fidelity" in the hematologic malignancies; the detection rate of both genes was much higher than that of the single gene. The application of the RQ-PCR method in the detection of IgH and TCRγ gene rearrangements in hematologic malignancies has important clinical significance in MRD monitoring.

Mapping quantitative trait loci for nitrogen uptake and utilization efficiency in rice (Oryza sativa L.) at different nitrogen fertilizer levels.

Genetic improvement is the fundamental basis for improving nitrogen-use efficiency. A better understanding of genetic factors controlling nitrogen uptake and utilization is required for crop genetic improvement. In this study, we identified the quantitative trait loci (QTLs) associated with traits of nitrogen uptake and utilization by using the single-sequence repeat marker method and a recombinant inbred line (RIL) population derived from a super hybrid Xieyou9308. All the traits investigated were inherited quantitatively by continuous variation and showed normal distribution in phenotype with transgressive segregation in the RIL population. Most of the traits were significantly correlated with each other except for nitrogen absorption ability (NAA) with nitrogen harvest index (NHI) and NHI with agricultural nitrogen-absorption efficiency (ANAE). At logarithmic odds value of 2.3, total 13 candidate QTLs, including 4 for NAA, 2 for NHI, 2 for physiological nitrogen-use efficiency, 1 for agricultural nitrogen-use efficiency (ANUE), and 4 for ANAE, were detected and mapped on chromosomes 2, 3, 4, 5, 8, 9, 10, and 12. Significant pleiotropic effect or neighboring expression of QTLs was observed among traits. At position 64.8 cM on chromosome 4 near the marker RM5757, there was a QTL cluster of NAA, ANUE, and ANAE, and at chromosome 5 near the marker RM5968, there was a QTL cluster of NAA and ANUE. The QTL clusters might provide partial explanation and genetic mechanism for the observed correlations between nitrogen uptake and utilization efficiency traits and might form a basis for future breeding programs.

Preoperative platelet count in predicting lymph node metastasis and prognosis in patients with non-small cell lung cancer.

Recent studies have shown an indirect link between platelet count and blood vessel metastasis, but this association with lymphatic vessels metastasis has not been established in NSCLC. So we investigated whether an association exists between preoperative platelet count and lymph node metastasis in NSCLC patients. Between January 2001 and January 2011, platelet counts were obtained from 883 NSCLC patients who were resistant to chemotherapy, radiotherapy, and surgery. The preoperative platelet counts, tumor metastasis, and overall survival of NSCLC patients were analyzed for correlations via statistical analysis. Upon considering patients according to their TNM lymph node metastasis stage (N0-N3), multiple comparison analyses revealed that the mean preoperative platelet count of the N0 group was significantly lower than that of the N1-N3. Analysis of variance showed that the preoperative platelet count of patients in stage I was significantly lower than that of those in stages II, III, and IV, with no significant difference among the latter three stages. According to the Kaplan-Meier survival analysis, the overall survival of patients with platelet counts <214.5 × 109/L was significantly longer than that of those with platelet counts ≥214.5 × 109/L. Cox regression analysis indicated that, besides preoperative platelet count, patient age, gender, and TNM stage were independent prognostic factors. In conclusion, preoperative platelet count was significantly associated with metastasis of lymph nodes in NSCLC patients. Preoperative platelet count may be a reliable biomarker of lymph node metastasis possibility and an independent prognostic factor of overall survival in patients with NSCLC.

Production of secoisolariciresinol from defatted flaxseed by bacterial biotransformation.

AIMS: Secoisolariciresinol (SECO) is increasingly recognized for potential clinical application because of its preventive effects against breast and colon cancers, atherosclerosis and diabetes, and its production through biotransformation has been attempted. However, previously reported bacteria all required stringent anaerobic culture conditions, precluding large-scale production. Here, we report the isolation and characterization of bacteria that produce SECO under less stringent anaerobic culture conditions. METHODS AND RESULTS: Using defatted flaxseed as raw material, we isolated a facultative anaerobic bacterium from human faeces that hydrolysed secoisolariciresinol diglucoside-3-hydroxy-3-methyl glutaric acid (SDG-HMGA) oligomers in flaxseed to produce SECO. Both conventional assays and 16S rRNA gene sequence analysis demonstrated its close relatedness with Bacteroides uniformis. The transformation efficiency of SDG in defatted flaxseed to SECO was more than 80% by this bacterial strain. We investigated factors that might influence fermentation, such as redox potential and pH, for large-scale fermentation of defatted flaxseed to produce SECO. CONCLUSIONS: The method to produce SECO through biotransformation of defatted flaxseed with this bacterial strain is highly efficient and economic. SIGNIFICANCE AND IMPACT OF THE STUDY: This bacterial strain can transform SDG to SECO under less stringent anaerobic culture conditions, which will greatly facilitate industry-scale production of SECO.

[Long-term outcomes of 328 patients with of autism spectrum disorder after fecal microbiota transplantation].

Objective: To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) in the treatment of autism spectrum disorder (ASD). Methods: A longitudinal study was conducted. Clinical data from ASD patients with gastrointestinal symptoms and who underwent FMT in the Tenth People's Hospital affiliated to Tongji University or Jinling Hospital between May 2012 to May 2021 were retrospectively collected. Scores derived from the autism behavior checklist (ABC), the childhood autism rating scale (CARS), the Bristol stool form scale (BSFS), and the gastrointestinal symptom rating scale (GSRS) were analyzed at baseline and at the 1st, 3rd, 6th, 12th, 24th, 36th, 48th and 60th month after FMT. Records of any adverse reactions were collected. Generalized estimating equations were used for analysis of data on time points before and after FMT. Results: A total of 328 patients met the inclusion criteria for this study. Their mean age was 6.1±3.4 years old. The cohort included 271 boys and 57 girls. The percentage of patients remaining in the study for post-treatment follow-up at the 1st, 3rd, 12th, 24th, 36th, 48th and 60th month were as follows: 303 (92.4%), 284 (86.7%), 213 (64.9%), 190 (57.9%), 143 (43.6%), 79 (24.1%), 46 (14.0%), 31 (9.5%). After FMT, the average ABC score was significantly improved in the first 36 months and remained improved at the 48th month. However, the average score was not significantly different from baseline by the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.108). The average CARS score improved significantly during the first 48 months and remained improved at the 60th month (1st-48th month, P<0.001; 60th month, P=0.010). The average BSFS score was also significantly improved in the first 36 months (with an accompanying stool morphology that resembled type 4). This improvement was maintained at the 48th month. However, the average score was similar to baseline at the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.109). The average GSRS score was significantly improved during the first 24 months, but not afterwards (1st-24th month, P<0.001; 36th month, P=0.209; 48th month, P=0.996; 60th month, P=0.668). The adverse events recorded during treatment included abdominal distension in 21 cases (6.4%), nausea in 14 cases (4.3%), vomiting in 9 cases (2.7%), abdominal pain in 15 cases (4.6%), diarrhea in 18 cases (5.5%), fever in 13 cases (4.0%), and excitement in 24 cases (7.3%). All adverse reactions were mild to moderate and improved immediately after suspension of FMT or on treatment of symptoms. No serious adverse reactions occurred. Conclusion: FMT has satisfactory long-term efficacy and safety for the treatment of ASD with gastrointestinal symptoms.

Evolution of diverse Hall effects during the successive magnetic phase transitions in Mn2.5Fe0.6Sn0.9 Kagome-lattice alloy.

Evolution of diverse Hall effects due to successive magnetic transitions has been observed in Mn2.5Fe0.6Sn0.9 by suitable chemical substitution of Fe in Mn3.1Sn0.9. This noncollinear antiferromagnetic alloy exhibits a Neel temperature of 325 K. Upon cooling from 325 K, a magnetic phase transition from noncollinear antiferromagnetism to ferromagnetism occurs at 168 K due to the tilting of magnetization towards c axis. Above this temperature, anomalous Hall resistivity ranged from 0.6 to 1.3 µΩ cm has been observed in noncollinear antiferromagnetic state. Below this temperature, a topological Hall effect (THE) starts to appear due to the non-vanishing scalar spin chirality arising from the noncoplanar spin structure. Further decreasing temperature to 132 K, another magnetic transition happens, resulting in the coexistence of ferromagnetism and antiferromagnetism, so that a Hall plateau with large hysteresis below 70 K is yielded. A hysteresis as high as ∼80 kOe is obtained in ρ xy -H at 15 K. However, the Hall plateau disappears and only anomalous Hall effect (AHE) persists when further decreasing the temperature to 5 K. The present study provides a picture of diverse magneto-transport properties correlated to the variable spin structures driven by magnetic phase transitions.

Follow-up management strategy for patients undergoing peritoneal dialysis during novel coronavirus pneumonia epidemic.

OBJECTIVE: The study aimed to explore the best follow-up management strategy for patients undergoing peritoneal dialysis (PD) during the novel coronavirus pneumonia (NCP) epidemic. PATIENTS AND METHODS: Patients undergoing PD who were followed up during the NCP epidemic by our hospital were enrolled in this study. Because of the need to control the epidemic, a follow-up system was established during the epidemic period, with WeChat, QQ, and the telephone as the main methods of communication. Outpatient and emergency follow-ups were carried out to ensure the safety of dialysis and the prevention and control of the epidemic. The follow-up strategy included response measures related to the epidemic situation, prevention of peritonitis related to PD, water and salt control, exercise guidance, and psychological care. According to the patient's condition, the appointment system was implemented, with one consulting room and one process for each patient. The emergency patients were isolated in accordance with the epidemic situation. RESULTS: Since January 2020, among the 580 patients undergoing PD who were followed up in our department and their families, none had NCP infection. During the epidemic period, the standard hemoglobin level and the inpatient rate decreased. Complications related to PD, such as peritonitis, cardiovascular complications caused by volume overload, and pulmonary infection, did not significantly increase, and the withdrawal rate and mortality rate decreased compared with those in the same period last year. CONCLUSIONS: The patient follow-up strategy during the epidemic period had a significant positive effect on preventing and controlling the epidemic. Furthermore, during the epidemic period, encouraging patients and caregivers to pay attention to protection at home, avoid going out, strengthen self-management, and other measures were beneficial to the control of kidney disease itself, which is worth promoting. The close relationship between doctors and patients during the epidemic had a positive effect on the occurrence of complications related to patients undergoing PD.

Prevalence of, and factors associated with, gastroesophageal reflux disease: a population-based study in Shanghai, China.

The prevalence of gastroesophageal reflux disease (GERD) in China is lower than that in the Western countries, but appears to be increasing. The aim of this pilot study was to evaluate the prevalence of GERD in Shanghai, China, and to explore which population characteristics where associated with GERD. A sample of 1200 adult inhabitants of Shanghai, selected using randomized, stratified, multi-stage sampling, completed Mandarin translations of the Reflux Disease Questionnaire and GERD Impact Scale. Potential risk factors for GERD were examined by nested case-control analysis, using Cochran-Armitage trend testing and logistic regression analysis. The response rate was 86.2%; 919 responses were suitable for analysis. The prevalence of GERD, defined as heartburn and/or regurgitation of any frequency during the previous week, was 6.2% in Shanghai. Obesity and urban dwelling were associated with GERD (odds ratio 3.4, 95% confidence interval 1.3-9.3; and odds ratio 3.6, 95% confidence interval 1.2-10.4, respectively). The prevalence of GERD in Shanghai agreed with previous Chinese studies. GERD in Shanghai was associated with obesity and residency in an urban environment.

Prediction of fully compensated ferrimagnetic spin-gapless semiconducting FeMnGa/Al/In half Heusler alloys.

Materials with full spin polarization that exhibit zero net magnetization attract great scientific interest because of their potential applications in spintronics. Here, the structural, magnetic and electronic properties of a C1 b -ordered FeMnGa alloy are reported using first-principles calculations. The results indicate that the corresponding band structure exhibits a considerable gap in one of the spin channels and a zero gap in the other thus allowing for high mobility of fully spin-polarized carriers. The localized magnetic moments of Fe and Mn atoms have an antiparallel arrangement leading to fully compensated ferrimagnetism, which possesses broken magnetic inversion symmetry. Such magnetic systems do not produce dipole fields and are extremely stable against external magnetic fields. Therefore, this will improve the performance of spintronic devices. Using this principle, similar band dispersion and compensated magnetic moments were predicted in a C1 b -ordered FeMnAl0.5In0.5 Heusler alloy.

Tailoring structural and magnetic properties of Mn3-x Fe x Ga alloys towards multifunctional applications.

This study investigated the structural and magnetic properties of Mn3-x Fe x Ga alloys (x = 0, 0.2, 0.4, 0.6, 0.8, 1) under different heat-treatment conditions. A tetragonal structure was observed in samples that were heat treated at 623 K for three days followed by quenching in ice water. These tetragonal alloys present large coercive fields in the range 0.8-5 kOe and low saturation magnetization, and have great potential for application in spin-transfer torque-based devices. A hexagonal structure was observed in samples subjected to heat treatment at 883 K for three days following quenching in ice water. A moderate decrease in the coercive field has been observed for the hexagonal alloys compared with those with a tetragonal structure. However, the Mn3-x Fe x Ga alloys with a hexagonal structure exhibit other attractive magnetic properties, including collinear and non-collinear magnetic properties, holding high promise for technological applications. A face-centred-cubic (f.c.c.) structure was observed when subjected to annealing at 1073 K for three days followed by quenching in ice water. In contrast to the tetragonal and hexagonal structures, all f.c.c. alloys exhibit antiferromagnetic behaviour. This versatile material can display a wide range of multi-functionalities attributed to its tuneable crystal structure. This investigation will guide the design of multiple structures of these materials in order to utilise the wide functionalities for practical applications.

[The application of 3D reconstruction in investigating the frontal sinus drainage pathway based on computer tomography data].

Objective:The aim of this study is to explore the value of 3D reconstruction technology based on computer tomography data in understanding the frontal sinus drainage pathway. Method:Three-dimensional reconstruction of DICOM data from 100 cases of sinus CT was performed by using Mimics 19.0 software. The 3D models were used to study types, the relative locations of frontal sinus and recess cells as well as the influence of the frontal sinus drainage pathway. Result:The 3D model of frontal sinus, frontal recess cells and frontal sinus drainage pathway were reconstructed successfully. Among them, the incidence of nasal cavity was 95.5% (191/200), nasal cavity was 31.5% (63/200), nasal cavity on the frontal air room was 24.5% (49/200) supra bulla cells were 54% (108/200), supra bulla frontal cells were 14.5% (29/200), supraorbital ethmoid cells were 20.5% (41/200), and the rate of frontal septal cells were 4% (8/200). It visually demonstrated the relationship between the frontal recess and the frontal sinus drainage channel. Conclusion:The 3D reconstruction technology based on computer tomography data not only helps us to understand the anatomy of the frontal sinus, the relative position of the frontal crypt and the effect on the frontal sinus drainage channel, but also provides a new method for preoperative planning and intraoperative guidance to endoscopic frontal sinus surgery.

Transition from Anomalous Hall Effect to Topological Hall Effect in Hexagonal Non-Collinear Magnet Mn3Ga.

We report experimental observation of large anomalous Hall effect exhibited in non-collinear triangular antiferromagnet D019-type Mn3Ga with coplanar spin structure at temperatures higher than 100 K. The value of anomalous Hall resistivity increases with increasing temperature, which reaches 1.25 µΩ · cm at a low field of ~300 Oe at room temperature. The corresponding room-temperature anomalous Hall conductivity is about 17 (Ω · cm)-1. Most interestingly, as temperature falls below 100 K, a temperature-independent topological-like Hall effect was observed. The maximum peak value of topological Hall resistivity is about 0.255 µΩ · cm. The appearance of the topological Hall effect is attributed to the change of spin texture as a result of weak structural distortion from hexagonal to orthorhombic symmetry in Mn3Ga. Present study suggests that Mn3Ga shows promising possibility to be antiferromagnetic spintronics or topological Hall effect-based data storage devices.

Species identification of Radix Astragali (Huangqi) by DNA sequence of its 5S-rRNA spacer domain.

About 300 species and varieties of Astragalus are identified in China, making the identification of the origin of a particular Astragalus species on the consumer market difficult. A molecular genetic approach was developed to identify various species of Astragalus. Although the 5S-rRNA coding sequence is conserved in higher eukaryotes, the spacer domain of the 5S-rRNA gene has great diversity among different species. The 5S-rRNA spacer domain was amplified by polymerase chain reaction (PCR) from the isolated genomic DNA, and the PCR products (approximately 300 bp) covering the 5S-rRNA spacer domain were sequenced. The nucleotide sequences of Astragalus membranaceus, A. membranaceus var. mongholicus, A. lehmannianus, A. hoantchy, and of one closely related species Hedysarum polybotrys (Hongqi), were determined. Diversity in DNA sequence and restriction enzyme mapping among various species was found in their 5S-rRNA spacer domains. This is the first report on the detection of 5S-rRNA spacer region sequence of Astragalus, and the results could be used for genetic identification of Huangqi.