[Value of absolute quantification of myocardial perfusion by PET in detecting coronary microvascular disease in patients with non-obstructive coronaries]

Objective: To compare the incidence of coronary microvascular disease (CMVD) between patients with non-obstructive and obstructive coronary arteries. Methods: We retrospectively analyzed 97 patients with angina pectoris, who underwent the absolute quantitative PET examination of myocardial perfusion and coronary anatomy examination within 90 days. All patients were divided into two groups: non-obstructive group (72 cases, no stenosis ≥50% in all three coronary arteries) and obstructive group (25 cases, at least one coronary stenosis ≥50%; and at least one coronary stenosis<50%). Quantitative parameters derived from PET including rest myocardial blood flow (RMBF), stress myocardial blood flow (SMBF), coronary flow reserve (CFR) and cardiovascular risk factors were compared between the two groups. CMVD was defined as CFR<2.90 and SMBF<2.17 ml·min(-1)·g(-1). Results: Incidence of CMVD was significant higher in the non-obstructive coronary arteries of the obstructive group than in the non-obstructive coronary arteries of non-obstructive group (47.1% (16/34) vs. 25.5% (55/216), χ(2)=6.738, P=0.009) while incidence of CMVD was similar between non-obstructive and obstructive patients ((44% (11/25) vs. 33.3% (24/72), χ(2)=0.915, P=0.339). RMBF ((0.83±0.14) ml·min(-1)·g(-1) vs. (0.82±0.17) ml·min(-1)·g(-1)), SMBF ((2.13±0.60) ml·min(-1)·g(-1) vs. (1.91±0.50) ml·min(-1)·g(-1)) and CFR (2.59±0.66 vs. 2.36±0.47) were similar between the two groups (all P>0.05). Conclusions: CMVD can occur in non-obstructive coronary arteries in both patients with non-occlusive coronary arteries and patients with obstructive coronary arteries. Prevalence of CMVD is significantly higher in patients with obstructive coronary arteries than in patients with non-obstructive coronary arteries. The CMVD severity is similar between the two groups.

Coadministration with Tea Polyphenols Enhances the Neuroprotective Effect of Defatted Walnut Meal Hydrolysate against Scopolamine-Induced Learning and Memory Deficits in Mice

The present study aimed to investigate the combined effects of defatted walnut meal hydrolysate (DWMH) and tea polyphenols (TP) on learning improvement and to explain mechanistically why the combined treatments were more effective than either subject alone. In the step-down avoidance test and the Morris water maze test, codelivery of DWMH and TP was more effective than either individual supplement in reversing memory impairment in scopolamine-treated mice. Mixing with TP significantly facilitated the protective effects of DWMH or DWMH-derived peptides (cationic peptide P1 and anionic peptide P2) on H₂O₂-injured SH-SY5Y cells. Although combination treatment with TP and DWMH did not significantly alter systemic exposure to P1 or P2 in rats, it significantly increased the accumulation of the two peptides in the mouse brain. In addition, TP significantly improved cellular uptake of P1 and P2 by brain capillary endothelial cells, indicating that TP enhanced the blood-brain barrier permeation of DWMH-derived peptides. The proposed explanation for the advantage of combined treatment with TP and DWMH in reversing memory impairment was that TP enhanced both the protective effects of DWMH on nerve cells and the accumulation of DWMH in the brain. Our study can aid efforts to develop products and investigate the effects of nutrient combinations on brain disorders.

Antioxidant and anti-aging effects of a sea cucumber protein hydrolyzate and bioinformatic characterization of its composing peptides

C. elegans-based activity guided and size-based isolation of antioxidant peptide fractions from a sea cucumber protein hydrolyzate and their bioinformatic characterization.

[Application of low temperature thermoplastic plate combined with special abdominal band in fixing abdominal pedicled flap for repairing 17 patients with deep electric burn wounds in hands]

If the abdominal pedicled flaps are not well fixed after repair of deep electric burn wounds in hands, many problems such as poor blood supply may occur. In order to solve the above problems, we designed and manufactured the individualized low temperature thermoplastic plate combined with special abdominal band to fix abdominal pedicled flaps for repairing of 17 patients (12 males and 5 females, aged 2-35 years) with deep electric burn wounds in hands from February 2016 to August 2018, and achieved the desired results. The shoulder joint, elbow joint, and wrist joint were fixed by low temperature thermoplastic plate according to the 1/2 circumference of the patient's side chest and upper arm, and the braking of wrist joint and elbow joint was strengthened by special abdominal band. Application of the combined method of fixing abdominal pedicled flaps in repairing deep electric burn wounds in hands has high success rate of flap transplantation. It is simple to make and practical, and worthy of clinical promotion.

Computer-Aided Diagnosis of Solid Breast Lesions With Ultrasound: Factors Associated With False-negative and False-positive Results

OBJECTIVES

To investigate factors that may lead to false-positive or false-negative results in a computer-aided diagnostic system (S-Detect; Samsung Medison Co, Ltd, Seoul, Korea) for ultrasound (US) examinations of solid breast lesions.

METHODS

This prospective study was approved by the Institutional Review Board of Sun Yat-sen Memorial Hospital. All patients signed and provided written informed consent before biopsy or surgery. From September 2017 to May 2018, 269 consecutive women with 338 solid breast lesions were included. All lesions were examined with US and S-Detect before biopsy or surgical excision. The final US assessments made by radiologists and S-Detect were matched to the pathologic results. Patient and lesion factors in the "true" and "false" S-Detect groups were compared, and multivariate logistic regression analyses were used to identify the factors associated with false S-Detect results.

RESULTS

The mean age of the patients ± SD was 42.6 ± 12.9 years (range, 18-77 years). Of the 338 lesions, 209 (61.8%) were benign, and 129 (38.2%) were malignant. Larger lesions, the presence of lesion calcifications detected by B-mode US, and grades of 2 and 3 according to Adler et al (Ultrasound Med Biol 1990; 16:553-559) were significantly associated with false-positive S-Detect results (odds ratio [OR], 1.071; P = .006; OR, 5.851; P = .001; OR, 1.726; P = .009, respectively). Smaller lesions and the absence of calcifications detected by B-mode US in malignant solid breast lesions were significantly associated with false-negative S-Detect results (OR, 1.141; P = .015; OR, 7.434; P = .016).

CONCLUSIONS

Larger benign lesions, the presence of lesion calcifications, and high degrees of vascularity are likely to show false-positive S-Detect results. Smaller malignant lesions and the absence of calcifications are likely to show false-negative S-Detect results.

Protein expressions of AIB1, p53 and Bcl-2 in epithelial ovarian cancer and their correlations with the clinical pathological features and prognosis

OBJECTIVE

To investigate the protein expressions of steroid receptor coactivator amplified in breast cancer 1 (AIB1), apoptosis-related protein p53 and B-cell lymphoma-2 (Bcl-2) in epithelial ovarian cancer; to analyze the correlations among the expressions of these three proteins; to explore their correlations with the clinical pathological features and prognosis.

MATERIALS AND METHODS

Immunohistochemistry streptavidin-peroxidase (IHC-SP) method was performed to detect the positive protein expressions of AIB1, Bcl-2, and p53 in the pathological sections of normal ovarian tissues, benign ovarian epithelial tumor, and epithelial ovarian cancer, thereby analyzing the protein expression rates of these genes in different pathological stages, lymphatic metastasis and postoperative recurrent ovarian cancer, and carrying out the correlation analysis of these three proteins.

RESULTS

Positive protein expressions of AIB1, Bcl-2, and p53 were identified in the epithelial ovarian cancer tissues, and with an increase in the tumor staging of ovarian cancer, we found that the positive protein expression rate was gradually augmented. Particularly in ovarian cancer with lymphatic metastasis and postoperative recurrence, the positive expression rate was almost 100%. The protein expression of AIB1 was positively correlated with those of the p53 and Bcl-2.

CONCLUSIONS

We showed that positive expressions of AIB1, Bcl-2, and p53 in ovarian cancer are closely correlated with the pathological staging, metastasis, and recurrence, and the positive protein expression suggests a poor prognosis.

Characterization of polycyclic aromatic hydrocarbons in urban-rural integration area soil, North China: Spatial distribution, sources and potential human health risk assessment

The promotion of urbanization has accelerated the development of small manufacturing workshops and brought serious environmental problems. In this study, spatial distribution, sources and potential health risk for polycyclic aromatic hydrocarbons (PAHs) in urban-rural integration area soil in North China (800 km²) were discussed. The average total concentration of 16 PAHs was 225 μg kg^-1, and range from 25 to 15155 μg kg^-1 (n = 250). According to the European soil quality standards, more than 70% of the samples don't reach the pollution level, while around the small workshop concentration area and non-ferrous metal smelter were more contaminated than other area. The spatial distribution of soil PAHs concentration shows that low molecular weight, medium molecular weight and high molecular weight is very similar to the distribution of total PAHs, indicating that is likely to be caused by point source pollution. The sources of PAHs were identified by positive matrix factorization. The main six sources in the region are coal and biomass combustion, creosote, coke tar, vehicle and oil, which is consistent with the local energy consumption structure. Finally, a deterministic assessment of the cancer risk showed that the range for children was 5.94 × 10^-8 to 2.53 × 10^-5, and adults it ranged from 2.11 × 10^-8 to 9.01 × 10^-6. There is not a carcinogenic risk value greater than 10^-4 in the entire region, but potential carcinogenic risks persisted in some areas. We conclude that PAHs pollution of soil in the area is an issue that deserves urgent attention for the relevant departments.

Evaluate the Malignancy of Pulmonary Nodules Using the 3-D Deep Leaky Noisy-OR Network

Automatic diagnosing lung cancer from computed tomography scans involves two steps: detect all suspicious lesions (pulmonary nodules) and evaluate the whole-lung/pulmonary malignancy. Currently, there are many studies about the first step, but few about the second step. Since the existence of nodule does not definitely indicate cancer, and the morphology of nodule has a complicated relationship with cancer, the diagnosis of lung cancer demands careful investigations on every suspicious nodule and integration of information of all nodules. We propose a 3-D deep neural network to solve this problem. The model consists of two modules. The first one is a 3-D region proposal network for nodule detection, which outputs all suspicious nodules for a subject. The second one selects the top five nodules based on the detection confidence, evaluates their cancer probabilities, and combines them with a leaky noisy-OR gate to obtain the probability of lung cancer for the subject. The two modules share the same backbone network, a modified U-net. The overfitting caused by the shortage of the training data is alleviated by training the two modules alternately. The proposed model won the first place in the Data Science Bowl 2017 competition.

The effects of temperature and dissolved oxygen on the growth, survival and oxidative capacity of newly hatched hybrid yellow catfish larvae (Tachysurus fulvidraco♀ × Pseudobagrus vachellii♂)

Demand for yellow catfish fry, an economically important farmed fish in China, has increased dramatically. Newly hatched larvae are highly sensitive to changes in environmental conditions, with water temperature (T) and dissolved oxygen (DO) being two important factors that affect their early development. We investigate optimal T (between 19.0 and 33.0 °C) and DO (between 2.0 and 12.0 mg L^-1) concentrations on growth and antioxidant enzyme activity of newly hatched hybrid yellow catfish larvae (Tachysurus fulvidraco × Pseudobagrus vachellii) using a central composite design. We use a response surface method to optimize the response variables for survival (S) and growth, and the reduction of oxidative stress, over a 50-day experimental duration. T has a significant effect on specific growth rate (SGR), hepatic malondialdehyde (MDA) content, and superoxide dismutase (SOD) and catalase (CAT) activities (P < 0.05). DO concentration has a significant effect on SGR, S, hepatic MDA content, and SOD and CAT activities (P < 0.05). T and DO also have significant second order effects on SGR, S, SOD, and CAT activities (P < 0.05). Increased DO at low T stimulates SOD and CAT activities and alleviates oxidative damage. Adjusted R² values for SGR, S, CAT, SOD, and MDA models are 0.734, 0.937, 0.916, 0.894 and 0.826, respectively. A combination of 26.8 °C and 7.3 mg L^-1 represents optimal rearing conditions, in that larval growth and antioxidant ability is improved. Results show that T and DO during larviculture of yellow catfish have important implications for aquaculture.

CiteSpace-based Document Information Visualization of Literature Published by Journal of Forensic Medicine from 1985 to 2018

Abstract

Objective To analyze a knowledge web of the literature published by Journal of Forensic Medicine from its founding in 1985 to 2018, describe the evolving process of forensic science research and explore the research hotspots and frontiers at present. Methods The literature that was published by Journal of Forensic Medicine from 1985 to 2018 was collected and analyzed in terms of elements, such as emerging research hotspots, high frequency keywords, authors, dispatching units, location of institution and funding, by CiteSpace5.3 information visualization analysis software. Results All disciplines of forensic medicine were continually developing and maturing, and the publication volume of the literature on forensic pathology had the highest weight; in research hotspots, the two categories, research and identification each had their own emphasis; as the main source of contributions to the journal, research institutes accounted for 38.99% of the total number of publications; Shanghai ranked first among all regions with 1 046 articles published. The number of funded articles was generally on the rise, with the number of funded articles published largest in 2015. Conclusion As an authoritative academic journal in the field of forensic science in China, Journal of Forensic Medicine carries the development of forensic science and witnesses the institutional reform of universities and colleges, and offers a wide range of communication and cooperation in terms of technicality and application. Many scholars and scientific research institutions have gained progress continually in various research directions in the form of teamwork; and emerging research hotspots will continue to play a huge role in future practical applications.

Functional Outcomes and New Vertebral Fractures in Percutaneous Vertebroplasty and Conservative Treatment of Acute Symptomatic Osteoporotic Vertebral Compression Fractures

OBJECTIVE

The present study compared the clinical functional outcomes and new vertebral compression fractures (NVCFs) between percutaneous vertebroplasty (PVP) and conservative treatment (CT) in patients with severe pain due to acute osteoporotic vertebral compression fractures (OVCFs). PVP has been increasingly used for the treatment of pain in patients with OVCFs. However, the effectiveness of the procedure and whether it causes NVCFs has remained controversial.

METHODS

A total of 544 eligible patients with OVCFs found on spinal radiographs and intractable back pain for ≤6 weeks were recruited from September 2012 to February 2018 and assigned to PVP (n = 280; 392 levels) or CT (n = 264; 366 levels). The visual analog scale and Oswestry Disability Index scores were determined before the intervention and at the 1-week and 1-, 3-, 6-, 12-, and 24-month follow-up examinations. In addition, monthly telephone follow-up interviews were performed. In the case of a sudden increase in back pain, the patient returned to the hospital for medical and magnetic resonance imaging examinations for NVCF detection.

RESULTS

The PVP group had significantly lower visual analog scale and Oswestry Disability Index scores than those for the CT group at 1 week and 1, 3, and 6 months (P < 0.05). However, the differences after 6 months were not statistically significant (P > 0.05). Similar numbers of NVCFs (total and adjacent fractures) were found at 24 months in both groups (P > 0.05).

CONCLUSIONS

Compared with CT, PVP provided a rapid decrease in pain and an early return to daily life activities, without an increase in the incidence of NVCFs.

[Keep the mission in mind and forging ahead bravely: thinking on the lead development of intensive medicine in Henan Province]

OBJECTIVE

With the establishment of clinical second-level discipline status, the development of critical care medicine in China has entered a rapid stage. Compared with the advanced provinces in China, the construction of critical care medicine in Henan Province started late but developed rapidly. In addition to the hospital treatment of severe patients, critical care medicine has played an important role in the past natural disasters and public health emergencies. The First Affiliated Hospital of Zhengzhou University is the hospital to establish the critical care discipline, which has led and witnessed the establishment and development of the critical care medicine specialty in the whole province. However, opportunities and challenges coexist, and there are still problems and difficulties in the development of critical care medicine, which need our thinking and solving.

miR-489-3p Regulates the Oxidative Stress Response in the Liver and Gill Tissues of Hybrid Yellow Catfish (Pelteobagrus fulvidraco♀ × P. vachelli♂) Under Cu2+ Exposure by Targeting Cu/Zn-SOD

Copper/zinc superoxide dismutase (Cu/Zn-SOD) plays critical roles in protecting cells and tissues against oxidative damage. Excessive copper ions (Cu2+) in water can damage the cells of aquatic organisms, leading to impaired growth and development and reduced antioxidant defenses. Many regulatory factors control the response to excess Cu2+. Among them, microRNAs (miRNAs) are important small RNAs that regulate the expression of their target genes and participate in the oxidative stress response. In the present study, we used bioinformatics and dual luciferase reporter gene analyses to demonstrate that the miR-489-3p of hybrid yellow catfish (Pelteobagrus fulvidraco♀ × P. vachelli♂) binds to the 3'-untranslated region (UTR) of its target gene, which encodes a Cu/Zn-SOD. The regulatory relationship between this miRNA and its target gene Cu/Zn-SOD was analyzed using qRT-PCR and luciferase activity assays. We also investigated the effect of the loss of miR-489-3p expression on the oxidative stress response of hybrid yellow catfish exposed to Cu2+. The Cu/Zn-SOD 3'UTR region was found to be fully complementary to positions 2-9 of the 5'-end seed region of miR-489-3p. The miR-489-3p expression levels were negatively related to Cu/Zn-SOD expression. Silencing of miR-489-3p up-regulated Cu/Zn-SOD expression in the liver and gill tissues, increased activities of SOD and catalase, and reduced the malondialdehyde content. This study is the first to demonstrate that miR-489-3p targets Cu/Zn-SOD to mediate the oxidative response to metal stress. These findings provide a theoretical basis for further studies on the response to oxidative stress caused by metals in cultured fish, and provide an experimental basis for the management of the culture environment.

Multiple time-frequency curve extraction Matlab code and its application to automatic bearing fault diagnosis under time-varying speed conditions

Vibration signal analysis is an important technique for bearing fault diagnosis. For bearings operating under constant rotational speed, faults can be diagnosed in the frequency domain since each type of fault has a specific Fault Characteristic Frequency (FCF), which is proportional to the shaft rotational speed. However, bearings often operate under time-varying speed conditions. Additionally, the measurement of the time-varying rotational speed requires instruments, such as tachometers, which leads to extra cost and installation. With the development of time-frequency analysis, the time-varying FCFs manifest as curves in the Time-Frequency Representation (TFR). It has been shown that extracting multiple time-frequency curves from the TFR and then identifying the Instantaneous Fault Characteristic Frequency (IFCF) and Instantaneous Shaft Rotational Frequency (ISRF), bearing faults can be automatically diagnosed under time-varying speed conditions without using tachometers. However, the existing method used to identify the IFCF and the ISRF may lead to inaccurate results. In this study, the complete MATLAB^© codes and a more reliable approach to use Multiple Time-Frequency Curve Extraction (MTFCE) for automatic bearing fault diagnosis under time-varying speed conditions are presented. •A Multiple time-frequency curve extraction (MTFCE) Matlab code is presented to extract multiple curves from the TFR.•Custom Matlab code for automatic bearing fault diagnosis under time-varying speed conditions without using tachometer data via the MTFCE is given and explained.•A new parameter, the allowable variance of the curve-to-curve ratio, is proposed to identify the IFCF and ISRF more reliably.

Unlocking the Lithium Storage Capacity of Aluminum by Molecular Immobilization and Purification

Aluminum is regarded as a promising alternative for graphite anode in next-generation lithium-ion batteries, but its application is hindered by the simultaneous presence of aluminum oxide and the huge volume changes. Herein, hydrogenation-induced self-assembly of robust Al nanocrystals with high purity that are uniformly anchored on graphene is demonstrated. The strong molecular interaction between Al and graphene can not only thermodynamically facilitate the homogenous distribution of Al on graphene but also effectively alleviate the volume changes and preserve the structural integrity of the electrode. More importantly, density functional theory calculations reveal that the absence of oxidation can lower the energy barrier for Li diffusion inside the Al matrix to less than 1/6 of that in an Al matrix with only one monolayer coverage of oxygen. These unique structural features enable the aluminum/graphene nanosheets (Al@GNs) electrode to realize a high reversible capacity of 1219 mAh g^-1 and an excellent cycling stability with capacity of 766 mAh g^-1 after 1000 cycles at the 3 A g^-1 rate. Furthermore, a full cell, comprising an Al@GNs anode and LiFePO₄ cathode, exhibits remarkable capacity retention of 96.4% after 100 cycles at the 0.5 A g^-1 rate.

Spatial Patterns of Brain Activity Preferentially Reflecting Transient Pain and Stimulus Intensity

How pain emerges in the human brain remains an unresolved question. Neuroimaging studies have suggested that several brain areas subserve pain perception because their activation correlates with perceived pain intensity. However, painful stimuli are often intense and highly salient; therefore, using both intensity- and saliency-matched control stimuli is crucial to isolate pain-selective brain responses. Here, we used these intensity/saliency-matched painful and non-painful stimuli to test whether pain-selective information can be isolated in the functional magnetic resonance imaging responses elicited by painful stimuli. Using two independent datasets, multivariate pattern analysis was able to isolate features distinguishing the responses triggered by (1) intensity/saliency-matched painful versus non-painful stimuli, and (2) high versus low-intensity/saliency stimuli regardless of whether they elicit pain. This indicates that neural activity in the so-called "pain matrix" is functionally heterogeneous, and part of it carries information related to both painfulness and intensity/saliency. The response features distinguishing these aspects are spatially distributed and cannot be ascribed to specific brain structures.

Plasma cell-free DNA integrity plus circulating tumor cells: a potential biomarker of no distant metastasis breast cancer

Cell-free DNA integrity (cfDI) is a promising diagnostic and prognostic biomarker in breast cancer. However, no specific study has evaluated the diagnostic ability of cfDI in patients with no distant metastasis breast cancer (no-MBC) and benign breast tumor (BBT) to date. We assessed the plasma cfDI of 84 patients with no-MBC and 30 patients with BBT using quantitative PCR and compared it with circulating tumor cells (CTCs) and carbohydrate antigen 153 (CA153). The no-MBC group had significantly lower mean cfDI (0.58) than the BBT group (0.74, p = 0.004). Subgroup analysis showed that decreased cfDI seem to be associated with risk factors such as age 14% (mean cfDI = 0.57), tumor size > 2 cm (mean cfDI = 0.58), and positive lymph node status (mean cfDI = 0.56), but had no statistical significance. McNemar's test suggested that cfDI had stronger diagnostic power than CTCs, cfDNA concentration, or CA153 (p < 0.001). Spearman's rho showed that the correlation coefficient between cfDI and CTCs was 0.278 (p = 0.04) in the no-MBC group. Receiver operating characteristic curve analysis also suggested that cfDI was superior to CTCs or CA153. Combined with CTCs, cfDI reduced the false positive rate from 50% to 10.71% and increased the area under the curve value from 0.66 to 0.68. Our results suggest that cfDI is a potential diagnostic biomarker of no-MBC. Using cfDI and CTCs as a combined diagnostic tool for no-MBC could improve diagnostic sensitivity and specificity but more samples will be needed.

Effects and mechanism of action of transcutaneous electrical acupuncture point stimulation in patients with abnormal semen parameters

Objective:

To evaluate the effect of transcutaneous electrical acupuncture point stimulation (TEAS) on sperm parameters and the underlying molecular mechanisms.

Methods:

A total of 121 patients diagnosed with oligozoospermia, asthenozoospermia or oligoasthenozoospermia were randomised into four groups (three treatment groups, one control): the TEAS groups were treated with 2 Hz (n=31), 100 Hz (n=31), or mock stimulation (n=29) at acupuncture points BL23, ST36, CV1 and CV4 for 2 months. The control group (n=30) was provided with lifestyle advice only.

Results

The changes in total sperm count and motility in the 2 Hz TEAS group were significantly greater than those in the mock group and the control group. The change in neutral α-glucosidase (NAG) and zinc levels in the 2 Hz group were significantly greater than those in the mock group and control group, and the changes in fructose levels of the 2 Hz group were significantly greater than those in the control group. Significant increases in calcium and integrin-binding protein 1 (CIB1) and reduction of cyclin-dependent kinase 1 b (CDK1) were also found after 2 Hz TEAS treatment.

Conclusions

The present findings suggest that 2 Hz TEAS can improve sperm count and motility in patients with abnormal semen parameters, and is associated with increases in seminal plasma zinc, NAG and fructose. The upregulation of CIB1 and downregulation of CDK1 by TEAS may be associated with its positive effects on sperm motility and count.

Trial registration:

http://www.chictr.org ; registration no. ChiCTR-TRC-11001775.

Antioxidative Effects and Mechanism Study of Bioactive Peptides from Defatted Walnut ( Juglans regia L.) Meal Hydrolysate

The peptide components of defatted walnut ( Juglans regia L.) meal hydrolysate (DWMH) remain unclear, hindering the investigation of biological mechanisms and exploitation of bioactive peptides. The present study aims to identify the peptide composition of DWMH, followed by to evaluate in vitro antioxidant effects of selected peptides and investigate mechanisms of antioxidative effect. First, more than 1 000 peptides were identified by de novo sequencing in DWMH. Subsequently, a scoring method was established to select promising bioactive peptides by structure based screening. Eight brand new peptides were selected due to their highest scores in two different batches of DWMH. All of them showed potent in vitro antioxidant effects on H₂O₂-injured nerve cells. Four of them even possessed significantly stronger effects than DWMH, making the selected bioactive peptides useful for further research as new bioactive entities. Two mechanisms of hydroxyl radical scavenging and ROS reduction were involved in their antioxidative effects at different degrees. The results showed peptides possessing similar capacity of hydroxyl radical scavenging or ROS reduction may have significantly different in vitro antioxidative effects. Therefore, comprehensive consideration of different antioxidative mechanisms were suggested in selecting antioxidative peptides from DWMH.

Research Status of New Designer Drug Methcathinone in Forensic Toxicology

Methcathinone, a new cathinone designer drug, which is structurally similar to amphetamine analogs, is a central nervous stimulant. Recently, there has been a worldwide rise in its popularity and abuse, and a growing number of cases with disability or even death is reported in several countries, resulting in public concern. The typical symptoms include accelerated heartbeat, high temperature, anxiety, depression, etc. Forensic studies on its toxicity mechanism are rare. This article reviews its toxicological effects, poisoning symptoms, poisoning and addiction mechanisms, and detection methods, to provide theoretical reference for future studies and guidance for related forensic identification.