A Giant Exchange Bias Effect Due to Enhanced Ferromagnetism Using a Mixed Martensitic Phase in Ni50Mn37Ga13 Spun Ribbons.

The structure of a material is an important factor in determining its physical properties. Here, we adjust the structure of the Ni50Mn37Ga13 spun ribbons by changing the wheel speed to regulate the exchange bias effect of the material. The characterization results of micromorphology and structure show that as the wheel speed increases, the martensite lath decreases from 200 nm to 50 nm, the structure changed from the NM to a NM and 10M mixed martensitic structure containing mainly NM, then changed to NM and 10M where 10M and NM are approaching. Meanwhile, HE first increased and then decreased as the wheel speed increased. The optimum exchange bias effect (HE = 7.2 kOe) occurs when the wheel speed is 25 m∙s-1, mainly attributed to the enhanced ferromagnetism caused by part of 10M in NM martensite, which enhanced the exchange coupling of ferromagnetism and antiferromagnetism. This work reveals the structural dependence of exchange bias and provides a way to tune the magnitude of the exchange bias of Heusler alloys.

Corrosion Behavior of Nitrogen-Containing Low-Nickel Weld Cladding in KCl-MgCl2 Eutectic Molten Salt at 900 °C.

In this paper, the element nitrogen (N) is used to partially replace the element nickel (Ni) in flux-cored wire. A 44%Ni-24%Cr-0.18N nitrogen-containing low-nickel flux-cored wire with excellent corrosion resistance is prepared. The corrosion behavior of nitrogen-containing low-nickel weld cladding and Inconel 625 weld cladding in 40 KCl + 60 MgCl2 (wt%) molten salt at 900 °C is studied. The results show that the selective dissolution of Cr occurs in both weld claddings. The corrosion resistance of the 44%Ni-24%Cr-0.18N nitrogen-containing low-nickel weld cladding is better than that of the Inconel 625 weld cladding. The reason is that added N can react with H+ in molten salt to generate NH4+, remove corrosive impurities of MgOH+ in molten salt and change the corrosion environment. N preferentially combines with Cr to form Cr2N, reduces the diffusion precipitation of Cr and improves the corrosion resistance.

Magnetic and Magnetostrictive Behaviors of Laves-Phase Rare-Earth-Transition-Metal Compounds Tb1-xDyxCo1.95.

The magnetic morphotropic phase boundary (MPB) was first discovered in Laves-phase magnetoelastic system Tb-Dy-Co alloys (PRL 104, 197201 (2010)). However, the composition-dependent and temperature-dependent magnetostrictive behavior for this system, which is crucial to both practical application and the understanding of transitions across the MPB, is still lacking. In this work, the composition-dependence and temperature-dependence of magnetostriction for Tb1-xDyxCo1.95 (x = 0.3~0.8) are presented. In a ferrimagnetic state (as selected 100 K in the present work), the near-MPB compositions x = 0.6 and 0.7, exhibit the largest saturation magnetization MS and the lowest coercive field HC; by contrast, the off-MPB composition x = 0.5, exhibits the largest magnetostriction, the lowest MS, and the largest HC. Besides, a sign change of magnetostriction is observed, which occurs with the magnetic transition across the MPB. Our results suggest the combining effect from the lattice strain induced from structure phase transition, and the influence of the MPB on magnetocrystalline anisotropy. This work may stimulate the research interests on the transition behavior around the MPB and its relationship with physical properties, and also provide guidance in designing high-performance magnetostrictive materials for practical applications.

Application of Smartphone Otoscope in Telemedicine in Rural Medical Consortium in Eastern China in the COVID-19 Era.

Purpose: This study aimed to evaluate the effectiveness of smartphone otoscope telemedicine in the rural medical consortium in East China in the COVID-19 era. Methods: This prospective study was conducted within a rural medical consortium that provides health care services by integrating medical resources in the same area. When a patient visited primary health care (PHC) for ear diseases, the PHC provider used a smartphone otoscope to examine the patient's external ear canal and eardrum, and then sent photos or videos of the patient's ear to the otolaryngologist at the lead hospital via WeChat group. The otolaryngologist provided remote diagnosis and management recommendations to the PHC provider. The following data were recorded: age and gender, outpatient diagnosis, disease duration, sides, duration of treatment, telemedicine visits, treatment outcomes, patient satisfaction, and PHC providers' self-evaluation score. Results: A total of 83 patients were included in the study, including 43 males and 40 females, with a mean age of 44.6 ± 19.7 years (range 3-83 years). The duration of treatment for these patients was 14.0 (7,14) days. PHC visits were 2.2 ± 1.1 times (range: 1-7 times). Telemedicine visits ranged from 1 to 5, with a mean of 1.8 ± 0.9. Among of patients, 62 (74.7%) were cured, 21 (25.3%) improved, and 0 (0%) were ineffective. Sixty-five patients (78.3%) were very satisfied, 16 (19.3%) patients were somewhat satisfied, and two patients (2.4%) were dissatisfied. Based on the self-reported helpfulness, the primary health care providers assessed telemedicine as very helpful (n = 63, 75.9%), helpful (n = 20, 24.1%), and unhelpful (n = 0, 0%). Conclusions: Smartphone otoscope telemedicine in the medical consortium can effectively improve the ability of rural PHC providers to diagnose and treat ear diseases, save time and costs for patients, and improve patient satisfaction.

A three-dimensional crosslinked nano-structure via in situ growth of carbon nanotube/cobalt sulfide composites on porous carbon nanofibers for enhanced sodium storage.

A three-dimensional crosslinked CFs@CNT/CoSx nanocomposite was successfully synthesized by in situ growing carbon nanotubes on carbon nanofibers and a facile sulfurization process. The carbon nanotubes synthesized by sintering melamine under the catalysis of cobalt can increase the specific surface areas and provide abundant sodium ion diffusion channels for the composite. Meanwhile, the formed cobalt sulfide nanoparticles will increase the active sites on the surface of CFs@CNT/CoSx. Due to the rational design of the composite structure, such an anode can deliver a specific capacity of 423.7 mA h g-1 after 100 cycles at 100 mA g-1 and exhibit superior rate performance of retaining 324.1 mA h g-1 at 2 A g-1 for sodium storage.

[Analysis on application value of Fu's subcutaneous needling for intercostal pain after surgery of osteoporotic thoracic vertebral compression fracture].

OBJECTIVE: To observe the effect of Fu's subcutaneous needling therapy on pain degree, quality of life, serum 5-hydroxytryptamine (5-HT) and neuropeptide Y (NPY) in patients with intercostal pain after surgery for osteoporotic thoracic vertebral compression fracture (OVCF) and explore the application value of Fu's subcutaneous needling in treatment of post-operative intercostal pain. METHODS: A total of 60 patients with intercostal pain after OVCF surgery were divided into a medication group and a Fu's subcutaneous needling therapy group, with 30 cases in each group. In the medication group, zoledronic acid injection, salmon calcitonin injection, calcitonin D tablets and mecobalamin tablets were prescribed. The duration of treatment was 8 weeks. In the Fu's subcutaneous needling therapy group, on the base of treatment as the medicine group, Fu's subcutaneous needling therapy was provided for 2 weeks，once every other day. The needle is inserted 6 cm away from the most painful point. Separately, in 2, 4 and 8 weeks of treatment, as well as in 16 weeks after treatment, the visual analogue scale (VAS) and the generic quality of life inventory-74 (GQOLI-74) were adopted to evaluate intercostal pain and quality of life in the patients of both groups and analyze the incidence of adverse reaction. Radioimmunoassay was used to measure the levels of serum 5-HT and NPY. RESULTS: Compared with the results before treatment, in 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS scores of both groups were all reduced (P<0.05), GQOLI-74 scores increased obviously (P<0.05) and the levels of serum 5-HT and NPY increased obviously (P<0.05) in the two groups. In 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS score in the Fu's subcutaneous needling therapy group was lower than that in the medication group (P<0.05), GQOLI-74 score and the levels of serum 5-HT and NPY were higher than those in the medication group (P<0.05). During the treatment and in 16 weeks after treatment, the difference was not significant in the incidence of adverse reaction between the two groups (P>0.05). CONCLUSION: Fu's subcutaneous needling therapy can relieve intercostal pain and improves the quality of life in the patients after surgery for OVCF.

Telemedicine for ear diseases with the smartphone otoscopes via WeChat in the COVID-19 era.

PURPOSE: This study aimed to evaluate the outcomes and satisfaction of ear patients who participated in the smartphone otoscopes telemedicine via WeChat. METHODS: Patients in this study included newly diagnosed outpatients and online patients who did not undergo an outpatient diagnosis. Patients performed regular ear self-examinations, took pictures at home using their smartphone endoscopes, and submitted images to a WeChat community. Otolaryngologist gave timely online feedback. All of the following data were recorded: patients age and gender, disease duration, outpatient diagnosis, side, telemedicine duration, number of telemedicine visits, outcomes, satisfaction. RESULTS: A total of 74 patients were included in the study, including 39 males and 35 females, with an average age of 31.1 ± 13.7 years (range 4-55 years). Of these patients, 68 were outpatients, and 6 directly participated in telemedicine online. The patient's disease duration ranged from 1 day to 15 days, with an average of 4.0 ± 3.0 days. The mean duration was 8.1 days (range: 3-21 days) for telemedicine. The mean number of visits was 2.7 times (range: 2-6 times) for telemedicine. 68 (91.9%) of the 74 patients were cured, 6 (8.1%) were improved, and 0 (0%) were ineffective. Almost all patients were pleased with the telemedicine service, 71.9 0% were very satisfied (n = 62), 28.10% were very satisfied (n = 11), and 0% were dissatisfied (n = 0). CONCLUSIONS: Smartphone otoscopes telemedicine can decrease outpatient follow-up, reduce the risk of cross-infection, increase telemedicine accuracy, and improve patient satisfaction. It is worthy of clinical application in the COVID-19 era.

Giant exchange bias induced via tuning interfacial spins in polycrystalline Fe3O4/CoO bilayers.

A giant exchange bias (EB) of 9600 Oe was observed in polycrystalline Fe3O4/CoO layers at 10 K after 20 kOe field cooling, and was attributed to the strong exchange coupling formed by the interfacial spins between the polycrystalline Fe3O4 and the CoO layer. It was found that at 10 K, the magnetic-moment difference (ΔM) between the zero field cooling curves and field cooling curves first increases and then decreases with the change of the field, and it reaches the maximum value at a field of 20 kOe, which suggests that the interfacial spins can be tuned by the cooling field. Furthermore, other magnetic properties, including field dependence, temperature dependence, and training effects, were investigated, which further confirmed that the interfacial spins play an important role in the EB effect. This work provides a method to tune the magnitude of the EB effect and reveals the mechanism of the dependency of EB on interfacial spins, which could guide the design of giant-EB-effect materials.

Dietary patterns of Chinese puerperal women and their association with postpartum weight retention: Results from the mother-infant cohort study.

Dietary intake may affect maternal health, but it remains unclear about puerperal dietary intake and its association with maternal health. This study investigated the dietary patterns and their related factors and association with postpartum weight retention (PPWR) in Chinese puerperal women. Participants were from the mother-infant cohort study, in which both mothers and infants were followed up from childbirth to the next 2 years, in seven cities around China. Maternal puerperal dietary patterns were derived by a food frequency questionnaire and principal component analysis (PCA) within 1 month postpartum. PPWR was assessed by the difference of weight at 42 days and 6 months postpartum minus the pre-pregnancy weight. Of 503 postpartum women, four dietary patterns were identified, including 'plant food' pattern (rice and vegetables as dominant foods), 'diverse' pattern (starchy roots, fruit, livestock meat and aquatic products), 'traditional northern' pattern (poultry, eggs and soup) and 'marine-flour' pattern (flour, coarse food grains and marine fish). The diverse pattern was associated with professional puerperal family care and counselling service (p < .05). PPWRs at 42 days and 6 months postpartum were 6.37 and 4.70 kg averagely. The plant food dietary pattern tended to be associated with higher 42-day PPWR (ß = .105, p < .05), and diverse pattern was associated with lower 6-months PPWR (ß = -.137, p < .05). Conclusively, this study presented four dominant dietary patterns in Chinese postpartum women and showed a lower PPWR in adherence to diverse dietary pattern. The results would provide evidence to furtherly guide dietary practice and improve maternal health.

Maternal postpartum feeding anxiety was associated with infant feeding practices: results from the mother-infant cohort study of China.

BACKGROUND: Maternal feeding anxiety (FA) was prevalent during puerperium and might affect infant feeding practices. This study was aimed to investigate the FA status in Chinese postpartum women and its relationship with infant feeding practices (FPs). METHODS: Participants were from the Mother-Infant Cohort Study of China, in which the dietary and feeding practices, physical and psychiatric health for both mothers and infants were followed up from childbirth to next 2 years. In this study the maternal feeding anxiety (FA) status at 0-3 months postpartum was assessed by Li's Self-rating Feeding Anxiety Scale (SFAS). Infant feeding practices (FPs) at 0-3 months, including breastfeeding-related behaviors, responsive feeding and infant food refusal were investigated by self-designed questionnaire. RESULTS: In total 456 mothers the average feeding anxiety scores (FAS) was 41.02 ± 8.02 (mean ± SD), and maternal FA prevalence were 61.4% (FAS>38) with severe FA being 8.6% (FAS>52) at 0-3 months postpartum. The FAS was related with infant FPs, and lower maternal FAS was significantly related with infant colostrum feeding (40.86 ± 8.02 vs 44.74 ± 11.33, P < 0.05), but higher FAS was related with bottle feeding (41.95 ± 8.28 vs 39.69 ± 7.92, P < 0.05). The mothers with severe feeding anxiety (FAS > 53) were more likely to feed infants with bottle (ORs, 95%CI: 2.41, 1.11 ~ 5.19). There were not significant association between FAS and exclusive breastfeeding and responsive feeding practices (P > 0.05). The higher FAS was associated with infant food refusal behaviors, the maternal scores whose infant "never", "rarely", "sometimes" and "often" spat out food when feeding were 39.86 ± 8.02, 41.47 ± 8.18, 41.36 ± 7.44 and 42.14 ± 12.03 increasingly (P > 0.05), and the FA prevalence was significantly different among groups (P < 0.05). The infants whose mother was identified as feeding anxiety were more likely to refuse opening the mouth when feeding (P < 0.05). Multivariate analysis indicated maternal FAS was positively related to infant bottle feeding (ßi = 2.487, P < 0.05) and outdoor sunshine exposure practice (ßi = 1.787, P < 0.05), and negatively related to household income level (ßi = - 0.118, P < 0.05). CONCLUSIONS: Maternal postpartum feeding anxiety was associated with some infant feeding practices, including bottle feeding and infant food refusal behaviors.

Improved magnetostriction in Galfenol alloys by aligning crystal growth direction along easy magnetization axis.

Galfenol (Iron-gallium) alloys have attracted significant attention as the promising magnetostrictive materials. However, the as-cast Galfenols exhibit the magnetostriction within the range of 20-60 ppm, far below the requirements of high-resolution functional devices. Here, based on the geometric crystallographic relationship, we propose to utilize the 90°-domain switching to improve the magnetostriction of Galfenols by tuning the crystal growth direction (CGD) along the easy magnetization axis (EMA). Our first-principles calculations demonstrate that Pt doping can tune the CGD of Galfenol from [110] to [100], conforming to the EMA. Then, it is experimentally verified in the (Fe0.83Ga0.17)100-xPtx (x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0) alloys and the magnetostriction is greatly improved from 39 ppm (x = 0, as-cast) to 103 ppm (x = 0.8, as-cast) and 188 ppm (x = 0.8, directionally solidified), accompanying with the increasing CGD alignment along [100]. The present study provides a novel approach to design and develop high-performance magnetostrictive materials.

Adjusting DBI-2016 to dietary balance index for Chinese maternal women and assessing the association between maternal dietary quality and postpartum weight retention: A longitudinal study.

Diet is believed to play a major role in maternal recovery, postpartum weight retention (PPWR) is one of the challenges for Chinese women. However, the association between puerperal women's diet and PPWR remained unclear and complicated in China. The study assessed the dietary quality of puerperal women using adjusted Chinese Dietary Balance Index-16 (DBI-16) and explored its associations with PPWR. Participants were enrolled in the Mother-Infant Cohort Study of China. Dietary intake and demographic characteristics were obtained by a semi-quantitative food frequency questionnaire and a self-designed questionnaire at 0-3 months postpartum. PPWR was calculated by the weight difference at 0-3months and 6-8months postpartum minus pre-pregnancy weight. Dietary quality was assessed using adjusted DBI-16. 316 puerperal women were enrolled. According to adjusted DBI-16, 84.8% of participants had an insufficient dietary intake (vegetables 84.8%, fruits 91.8%, dairy 87.3%, soybean 61.4% and aquatic foods 79.4%, respectively), 67.1% had an excessive intake (cereals 60%, meat 57.3% and eggs 64.9%, respectively), 98.4% had an imbalanced diet consumption. PPWR at 0-3, and 6-8 months were 6.0 (±5.1) kg and 5.2 (±7.7) kg, and the percentage of PPWR (≥5kg) were 63.0% and 52.8% respectively. Multivariable linear regression showed the intake of fish and shrimp at 0-3 months postpartum was negatively associated with PPWR at 6-8 months (ß = -0.114, SE = 0.279, p < 0.05). The diet quality of Chinese puerperal women was unreasonable and imbalanced. Fish intake tended to be a favorable factor for postpartum weight loss.

COVID-19 and anosmia: A review based on up-to-date knowledge.

The pandemic of Coronavirus Disease 2019 (COVID-19) has caused a vast disaster throughout the world. There is increasing evidence that olfactory dysfunction can present in COVID-19 patients. Anosmia can occur alone or can be accompanied by other symptoms of COVID-19, such as a dry cough. However, the pathogenic mechanism of olfactory dysfunction and its clinical characteristics in patients with COVID-19 remains unclear. Multiple cross-sectional studies have demonstrated that the incidence rate of olfactory dysfunction in COVID-19 patients varies from 33.9-68% with female dominance. Anosmia and dysgeusia are often comorbid in COVID-19 patients. Otolaryngologists should be mindful of the symptom of anosmia in outpatients so as not to delay the diagnosis of COVID-19. In this paper, we have reviewed the relevant knowledge based on up-to-date literature.

First demonstration of simultaneous measurement of beam current, beam position, and beam tilt on induction linac using combined B-dot monitor.

The authors previously reported that the axial B-dots can be used to directly measure the beam tilt and demonstrated that the axial B-dots are applicable to a coaxial calibration stand. In this study, a combined B-dot monitor composed of four axial B-dot loops and four azimuthal ones is tested for the simultaneous measurement of the time-varying beam current, beam offset, and beam tilt at the output of the injector of the DRAGON-I induction linac. In the experiments, the beam offset and beam tilt at the position of the monitor are proportionally adjusted using a pair of steering coils. Eight waveforms acquired from the B-dot monitor are analyzed to reconstruct the time-varying beam current, beam offset, and beam tilt. The original signals of both the azimuthal B-dot and the axial B-dot ports change significantly with respect to the current applied to the steering coils. The measured beam tilt is linearly dependent on the current applied to the steering coils and agrees well with the measured beam offset.

Effects of goat milk-based formula on development in weaned rats.

OBJECTIVE: The aim of this article is to study the effect of goat milk-based formula (GMF) on development in weaned rats. METHODS: One hundred Sprague-Dawley rats were randomly divided into five groups: control, 20% cow milk-based formula (CMF), and 5%-GMF, 10%-GMF, and 20%-GMF groups. RESULTS: GMF did play an active role in accelerating body and femur length, but not body weight growth. Compared with the control, GMF had better cognitive, space, and locomotor activity. The level of IFN was increased in GMF groups, as well as the level of IL-2 and TNF was decreased in GMF groups. CONCLUSION: These results indicate that GMF has an effect on development and immunity improvability in weaned rats.

Comparison of growth and nutritional status in infants receiving goat milk-based formula and cow milk-based formula: a randomized, double-blind study.

OBJECTIVE: To compare the growth and nutritional status of infants fed goat milk-based formula (GMF) and cow milk-based formula (CMF). METHODS: The study was conducted in Beijing, China. It was a double-blind randomized controlled trial. A total of 79 infants aged 0-3 months old were recruited and randomized in GMF or CMF group. The infants were fed the allocated formula to 6 months. The weight, length, and head circumference were measured at the enrolment, 3 and 6 months. The start time and types of solid food were recorded. Blood elements, urinal, and fecal parameters were also tested. RESULTS: The average weight of infants in the GMF group (mean±SD) was 4.67±0.99 kg and in the CMF group 4.73±1.10 kg at enrolment, and 8.75±0.98 kg (GMF) and 8.92±0.88 kg (CMF) at 6 months. There were no differences in the adjusted intention-to-treat analyses of weight, length, head circumference, and BMI z-scores between the two formula-fed groups over the 6-month study. Similarly, there were no remarkable differences in the timing and types of solid food, blood elements, urinal, and feces parameters, between the GMF and CMF group. No group differences have been shown in bowel motion consistency, duration of crying, ease of settling, or frequency of adverse events. CONCLUSIONS: GMF-provided growth and nutritional outcomes did not differ from those provided by CMF.

Effects of a concomitant single oral dose of rifampicin on the pharmacokinetics of pravastatin in a two-phase, randomized, single-blind, placebo-controlled, crossover study in healthy Chinese male subjects.

BACKGROUND: Pravastatin is a potent cholesterol-lowering agent; ~34% of an oral dose of pravastatin is eliminated unchanged through biliary and urinary excretion. Rifampicin is an inducer of drug metabolism enzymes, and it affects the activities of transporters involved in pravastatin disposition. Drug-drug interaction between rifampicin and pravastatin is possible because of the effects of rifampicin on the activities of drug transporters. OBJECTIVE: This study was designed to investigate the effects of a single oral dose of rifampicin on the pharmacokinetics of pravastatin. METHODS: Healthy Chinese male volunteers were recruited for this 2-phase, single-blind, placebo-controlled, crossover study. The subjects were randomly divided into 2 groups to receive either rifam-picin or placebo concomitantly with pravastatin. All subjects received a 20-mg oral dose of pravastatin on days 1 and 9, separated by an 8-day washout period. Subjects in the rifampicin group received a single 600-mg oral dose of rifampicin on day 1 and placebo on day 9; those in the placebo group received placebo on day 1 and a single 600-mg oral dose of rifampicin on day 9. High-performance liquid chromatography-tandem mass spectrometry was used to determine plasma concentrations of pravastatin for up to 12 hours after administration. RESULTS: Twelve volunteers participated in the study (6 per group). The mean (SD) age of the subjects was 20 (2) years (range, 18-25 years). The mean height of the subjects was 174 (4) cm (range, 168-180 cm), and the mean weight was 69.2 (3.7) kg (range, 65-77 kg). The mean pharmacokinetic parameters for pravastatin that changed significantly were as follows (rifampicin and placebo groups, respectively): C(max) (315.7 [227.2] and 115.8 [77.5] ng . mL(-1) [P = 0.009]); AUC(0-12) (604.8 [73.3] and 259.0 [133.4] ng . h . mL(-1) [P < 0.001]); AUC(0-infinity)) (623.3 [248.8] and 275.1 [58.5] ng . h . mL(-1) [P < 0.001]); and apparent oral clearance (CL/F) (0.52 [0.18] and 1.30 [0.58] L . h(-1) . kg(-1) [P < 0.001]). No significant changes in the T(max) or t((1/2)) of pravastatin were observed. All subjects tolerated pravastatin well during both phases of the study, with or without coadministration of rifampicin. None of the subjects withdrew from the study. CONCLUSION: Coadministration of a single oral dose of rifampicin significantly increased the plasma concentration of pravastatin in this group of healthy Chinese male subjects.

[Simultaneous determination of 5 sedative hypnotics in human plasma by reversed phase high-performance liquid chromatography].

OBJECTIVE: To determine diazepam, nitrazepam, oxazepam, estazolam, and alprazolam simultaneously in human plasma by reversed phase high-performance liquid chromatography (RP-HPLC). METHODS: Ten microliter carbamazepine (50 mg/L)as the internal standard was added into 1 mL sample, which contained the 5 mixed sedative hypnotics as standard substance and human plasma as ground substance. They were extracted with acetoacetate from plasma samples, and then were dissolved by 100 microL mobile phase. The blood drug levels were analyzed by high performance liquid chromatograph with 20 microL sample injection on a chromatographic column C18 (4.6 mm x 250 mm) at 30 degree. The mobile phase consisted of methanol and water (65:35),and the flow rate was 1.0 mL/min.The ultraviolet detection wavelength was 230 nm. RESULTS: The linearity range of the 5 drugs was 5-1,200 microg/L (r> or =0.9966, P<0.05). The recovery rate was 95.5%-105.6%. The extraction recovery rate was more than 75%. The relative standard deviation (RSD) of intra-day and inter-day was less than 10% (n=5). CONCLUSION: RP-HPLC method is convenient, accurate and sensitive for simultaneous determination of the concentration of diazepam, nitrazepam, oxazepam, estazolam, and alprazolam in human plasma.