A case of phenibut withdrawal and treatment with baclofen

Phenibut(β-phenyl-γ-aminobutyric acid)is a psychoactive gamma-aminobutyric acid(GABA)analog marketed online as a nutritional and nootropic(cognition enhancing)supplement.Phenibut consumption poses a high risk of potential abuse.Withdrawal from phenibut mimics benzodiazepine and alcohol withdrawal and can be dangerous.A number of approaches have been described for phenibut withdrawal,including protocols that include baclofen,but for inpatient and outpatient use.Here we describe a 30-year-old male who presented to an emergency department(ED)with insomnia,anxiety and palpitations after he stopped taking phenibut.

Withdrawal Intention of Farmers from Vacant Rural Homesteads and Its Influencing Mechanism in Northeast China: A Case Study of Jilin Province

The effective use of land in Northeast China is of great significance for ensuring national food security and regional rural revitalization.In this study,based on the survey data collected from Jilin Province,Northeast China,we analyzed the vacancy rates of rural homesteads in suburban,outer suburban,and remote villages,as well as the withdrawal intention of rural-settled farmers,urbansettled farmers,and farmers with urban and rural dual residency from vacant homesteads.From the perspective of farmers’perceptions,this study constructed a theoretical framework of the influence mechanism of their withdrawal intention and analyzed such mechanism by constructing a structural equation model.The results indicated that:1)rural homestead vacancy rates increased with distance from the village to the city.2)rural-settled farmers showed a low withdrawal intention for vacant rural homesteads,followed by urban and rural dual-residence farmers,and urban-settled farmers showed the highest withdrawal intention.3)the relative importance of the factors influencing withdrawal intention is in the following order:policy awareness>interest perception>living environment perception>family characteristics.Finally,this study discussed the reformation of the homestead system and rural homestead transition in Northeast China,which can provide policy support to increase the potential of cultivated land and promote sustainable rural development and urban-rural coordination.

Thermal behavior of the HTR-10 under combined PLOFC and ATWS condition initiated by unscrammed control rod withdrawal

Two tests initiated by unscrammed control rod withdrawal were performed on the High Temperature GasCooled Reactor-Test Module(HTR-10) in November 2003 after the reactor achieved its full power, and the test conditions represented a typical transient scenario of modular high-temperature reactors(HTRs), called pressurized loss of forced cooling, and anticipated transient without scram.Based on the test parameters, the HTR-10 thermal behaviors under the test conditions were studied with the help of the system analysis code THERMIX. The combination of the test results and the investigation results makes the HTR-10 safety potential better understood. Key phenomena, such as the helium natural circulation and the temperature redistribution in the reactor, were revealed. As the safety feature of most significance, there is a large margin between the maximum fuel temperature and its safety limit in each test. Temperatures of thermocouples in different components were calculated by THERMIX and compared with the test values. The applicability of the code was verified by good agreement obtained from the comparison.

Effects of electro-acupuncture on brain tissue norepinephrine contents in a morphine withdrawal anxiety mouse model

BACKGROUND： Following morphine withdrawal, anxiety is associated with abnormal norepinephrine content change. However, increasing blood lactic acid content can induce anxiety or panic in patients with anxiety disorder or endogenous opioid peptide functional disorder. OBJECTIVE： This study was designed to observe the effects of electro-acupuncture, at the ＂Sanyinjiao＂ point （SP 6）, on brain tissue norepinephrine and blood lactic acid content in anxiety-model mice after morphine withdrawal. DESIGN： A randomized controlled animal experiment. SETTING： This study was performed in the Laboratory of Acupuncture, Electro-acupuncture ＆ Tuina College, Chengdu University of Traditional Chinese Medicine, from June to September 2001. MATERIALS： A total of 50 healthy Kunming male mice were provided by the Laboratory Animal Center of Chengdu University of Traditional Chinese Medicine. The protocol was performed in accordance with ethical guidelines stated in the Guide for the use and care of laboratory animals, approved by the Committee on the Care and Use of Laboratory Animals of the Institute of Laboratory Animal Resources Commission on Life Sciences, National Research Council, China （1985）. Experimental reagents and equipment used were as follows： morphine hydrochloride （Lot No. 930503, Shenyang No.1 Pharmaceutical Factory, China）, norepinephrine （Sigma Chemical Company, USA）, fluorospectrophotometer （RF-510, Shimadzu Corporation, Japan）, Han electro-acupuncture apparatus （WQ 1002, No. zun （91）-227270-588, Beijing Anlong Photoelectricity-Technique Company, China）, and T-maze （self-made）. METHODS： A total of 50 mice were randomly divided into 5 groups, with 10 mice in each group： blank control, T-maze, model, model ＋ electro-acupuncture, and electro-acupuncture groups. Establishment of anxiety model after morphine withdrawal： the mouse hot plate assay was used to detect the activity of morphine. The median effective dose of morphine, 2.95 mg/kg, was defined as the base. Mice were subcutaneously administered morphine, 3 times a day, for 4 days successively （initially 2.95 mg/kg, then increased day by day, as described below）. Interventions： In the model ＋ electro-acupuncture group, after model induction, mice were subjected electro-acupuncture at bilateral ＂Sanyinjiao＂ （SP6） points using a Han electro-acupuncture apparatus with sparse-dense waves and frequency of 2-100 Hz, once a day, for 6 days. In the model group, after anxiety-model induction, mice were subjected to fixation as same as model ＋ electro-acupuncture group within 6 days of model induction. In the electro-acupuncture group, the anxiety model was not induced and mice were subjected to fixation, electro-acupuncture and the T-maze test. In the T-maze group, the anxiety model was not induced and mice were subjected to fixation. The T-maze test was performed in the 4 groups after experiment. In the blank control group, the anxiety model was not induced and mice were subjected to fixation only. MAIN OUTCOME MEASURES： Brain tissue norepinephrine content of morphine-withdrawal anxiety mice was detected by fluorospectrophotometry after 6 days of electro-acupuncture. Blood lactic acid content was detected by visible spectrophotometry. RESULTS： A total of 50 mice were included in the final analysis. Brain norepinephrine content was significantly greater in the model group compared to the T-maze, blank control, electro-acupuncture and model ＋ electro-acupuncture groups, （P 〈 0.05-0.01）. Brain norepinephrine content was similar between the model ＋ electro-acupuncture and the blank control groups （P 〉 0.05）. There was no significant difference in blood lactic acid content among the groups （P 〉 0.05）. CONCLUSION： Electro-acupuncture lowers brain norepinephrine content but does not influence peripheral blood lactic acid content in morphine-withdrawn, anxiety-modeled mice. These results demonstrate that anxiety-inhibiting effects of electro-acupuncture, after morphine withdrawal, might be related to regulation of norepinephrine release.

Withdrawal of anti-tumour necrosis factor α therapy in inflammatory bowel disease

Anti-tumour necrosis factor α(anti-TNFα) therapy is an established treatment in inflammatory bowel disease.However, this treatment is associated with high costs and the possibility of severe adverse events representing a true challenge for patients, clinicians and health care systems.Consequently, a crucial question is raised namely if therapy can be stopped once remission is achieved and if so, how and in whom.Additionally, in a real-life clinical setting, discontinuation may also be considered for other reasons such as the patient's preference, pregnancy, social reasons as moving to countries or continents with less access, or different local policy or reimbursement.In contrast to initiation of anti-TNFα therapy guidelines regarding stopping of this treatment are missing.As a result, the decision of discontinuation is still a challenging aspect in the use of anti-TNFα therapy.Currently this is typically based on an estimated, case-by-case, benefit-risk ratio.This editorial is intended to provide an overview of recent data on this topic and shed light on the proposed drug withdrawal strategies.

Anti-virus prophylaxis withdrawal may be feasible in liver transplant recipients whose serum HBeAg and HBV DNA are negative

Anti-virus prophylactic therapy may be not nec- essary for the prevention of hepatitis B virus （HBV） recur- rence after HBV-related liver transplantation （LT）. However, studies on completely stopping the hepatitis B immune globu- lin （HBIG） and nucleos（t）ide analogs （NUC） after LT are few. The aim of the current study was to evaluate the safety of anti- virus prophylaxis withdrawal in liver recipients whose serum hepatitis B e antigen （HBeAg） and HBV DNA are negative. We analyzed 190 patients undergone LT for HBV-related liver dis- ease from 2006 to 2012 and found that 10 patients completely stopped the HBIG and NUC due to poor compliance. These patients were liver biopsied and checked monthly with serum HBV markers, HBV DNA and liver function. Among the 10 patients, 9 did not show the signs of HBV recurrence after a mean follow-up of 51.6 months （range 20-73） after with- drawal of the HBIG and NUC. The average time from LT to the withdrawal of the anti-virus drug was 23.8 （13-42） months; one patient showed hepatitis B surface antigen-positive and detectable HBV DNA after stopping anti-virus drugs and this patient was successfully treated with entecavir. Our data sug- gested that complete withdrawal of anti-virus prophylaxis was safe and feasible for patients whose serum HBeAg and HBV DNA were negative at the time of LT.

Withdrawal of immunosuppression in liver transplantation and the mechanism of tolerance

BACKGROUND： Immunosuppression reagents have side effects and cause considerable long-term morbidity and mortality in patients after liver transplantation. Sufficient evidences showed that minimization or withdrawal of immunosuppression reagents does not deteriorate the recipient＇s immune response and physiological function and therefore, is feasible in some recipients of liver transplantation. However, the mechanisms are not clear. The present review was to update the current status of immunosuppression in liver transplantation and the mechanism of minimization or withdrawal of immunosuppression in liver recipients.DATA SOURCES： We searched articles in English on minimization or withdrawal of immunosuppression in liver transplantation in Pub Med. We focused on the basic mechanisms of immune tolerance in liver transplantation. Studies on immunosuppression minimization or withdrawal protocols and biomarker in tolerant recipients were also analyzed.RESULTS： Minimization or withdrawal of immunosuppression can be achieved by the induction of immune tolerance, which may not be permanent and can be affected by various factors. However, accurately evaluating immune status post-transplant is a prerequisite to achieve individualized immunosuppression. Numerous mechanisms for immune tolerance have been found, including immunophenotypic shift of memory CD8＋ T cells and CD4＋ T cell subsets. Activation of the inflammasome through apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain（ASC） in dendritic cells is associated with rejection after liver transplantation. CONCLUSIONS： Minimization or withdrawal of immunosuppression can be achieved by the induction of immune toler-ance via different mechanisms. This process could be affected by immunophenotypic shift of memory CD8＋ T cells and CD4＋ T cell subsets, which may be correlated with activation of the inflammasome through ASC in dendritic cells.

The withdrawal of the U.S. from the Paris Agreement and its impact on global climate change governance

The global community has prepared for the withdrawal of the U.S. from the Paris Agreement since Donald Trump was elected as the president of the U.S. However, Trump's formal declaration of withdrawal still caused worldwide reaction. Trump will use the withdrawal to build his political reputation and to renegotiate the Paris Agreement despite its negative effects on the political credibility, international relationships, and potential long-term economic growth of the U.S. In general, the withdrawal of the U.S. from the Paris Agreement will not change the development of low-carbon technologies and the transformation trend of the global climate governance regime. However, the long-term goals and international cooperation on climate change will be affected by budget cuts in American climate change research and the cancelation of donations from the multilateral environmental fund of the U.S. If the Paris Agreement is renegotiated, the common but differentiated principle of responsibility of the United Nations Framework Convention on Climate Change will be challenged again. Nevertheless, climate change governance remains a main theme of future sustainable development. Instead of national governments, local governments and non-governmental organizations will develop strategies for technical innovation and emphasize pragmatic cooperation, thus expanding their roles in climate change governance. The capacity building on climate change research and public awareness should be enhanced as a long-term objective of global climate change governance.

The impacts of U.S. withdrawal from the Paris Agreement on the carbon emission space and mitigation cost of China, EU, and Japan under the constraints of the global carbon emission space

Based on the Computable General Equilibrium (CGE) model and scenario analysis, the impacts of the U.S. withdrawal from the Paris Agreement on the carbon emission space and mitigation cost in China, European Union (EU), and Japan are assessed under Nationally Determined Contributions (NDCs) and 2
C scenarios due to the changed emission pathway of the U.S. The results show that, under the condition of constant global cumulative carbon emissions and a fixed burden-sharing scheme among countries, the failure of the U.S. to honor its NDC commitment to different degrees will increase the U.S. carbon emission space and decrease its mitigation cost. However, the carbon emission space of other parties, including China, EU, and Japan, will be reduced and their mitigation costs will be increased. In 2030, under the 2
C target, the carbon price will increase by 4.4e14.6 US$ t1 in China, by 9.7e35.4 US$ t1 in the EU, and by 16.0e53.5 US$ t1 in Japan. In addition, China, EU, and Japan will incur additional Gross Domestic Production (GDP) loss. Under the 2
C target, the GDP loss of China would increase by US$22.0e71.1 billion (equivalent to 16.4e53.1 US$ per capita), the EU's GDP loss would increase by US$9.4e32.1 billion (equivalent to 20.7e71.1 US$ per capita), and Japan's GDP loss will increase by US$4.1e13.5 billion (equivalent to 34.3e111.6 US$ per capita).

Methylene blue protects mitochondrial respiration from ethanol withdrawal stress

Methylene blue (MB), a tricyclic phenothiazine drug, has been reported to enhance mitochondrial functions including mitochondrial respiration. By comparison, stress associated with abrupt ethanol withdrawal (EW) impedes mitochondrial functions. We investigated whether MB protects mitochondrial respiration and cell survival from EW stress through a key mitochondrial enzyme, cytochrome c oxidase (COX). We also investigated whether the MB’s protection involves the inhibition of an excitatory neurotransmitter, glutamate. Male rats were exposed to and withdrawn from ethanol-diet (7.5%, 5 weeks). MB (0.5 mg/kg, intraperitoneal) was injected for the last 5 days of ethanol-diet and on the first day of EW. Cerebellum was then harvested to measure mitochondrial respiration and COX expression using real-time XF respirometer and immunohistochemistry, respectively. Separately, HT22 cells (a murine hippocampal cell line) were exposed to and abruptly withdrawn for 4 hours from chronic ethanol (100 mM, 3 days). MB was administered during EW with or without a COX inhibitor (NaN3) or glutamate. Mitochondrial respiration, COX content, and cell viability were then assessed using real-time XF respirometer, an immunoblot method, and Calcein assay, respectively. MB attenuated the suppressing effects of EW on mitochondrial respiration, COX content, and cell survival. This protection was reduced after NaN3 or glutamate cotreatment. These results suggest that MB treatment help maintain mitochondrial respiratory and cellular integrity through COX-upregulation and glutamateinhibition upon EW stress. MB treatment may help identify mitochondrial mechanisms underlying hyperexcitatory CNS disorders.

A Concise Model and Analysis for Heat-Induced Withdrawal Reflex Caused by Millimeter Wave Radiation

In this study, we consider the heat-induced withdrawal reflex caused by exposure to an electromagnetic beam. We propose a concise dose-response relation for predicting the occurrence of withdrawal reflex from a given spatial temperature profile. Our model is distilled from sub-step components in the ADT CHEETEH-E model developed at the Institute for Defense Analyses. Our model has only two parameters: the activation temperature of nociceptors and the critical threshold on the activated volume. When the spatial temperature profile is measurable, the two parameters can be determined from test data. We connect this dose-response relation to a temperature evolution model for electromagnetic heating. The resulting composite model governs the process from the electromagnetic beam deposited on the skin to the binary outcome of subject’s reflex response. We carry out non-dimensionalization in the time evolution model. The temperature solution of the non-dimensional system is the product of the applied power density and a parameter-free function. The effects of physical parameters are contained in non-dimensional time and depth. Scaling the physical temperature distribution into a parameter-free function greatly simplifies the analytical solution, and helps to pinpoint the effects of beam spot area and applied power density. With this formulation, we study the theoretical behaviors of the system, including the time of reflex, effect of heat conduction, biological latency in observed reflex, energy consumption by the time of reflex, and the strategy of selecting test conditions in experiments for the purpose of inferring model parameters from test data.

One-dimensional consolidation of visco-elastic aquitard due to withdrawal of deep-groundwater

One-dimensional consolidation of visco-elastic aquitard due to withdrawal of deep-groundwater was studied.Merchant model was used to simulate visco-elastic characteristic of aquitard.General solutions of the governing equation were obtained by applying Laplace transform with respect to time,and then the pore-pressure,strain and deformation of the aquitard could be calculated by Laplace inversion.A case was analyzed to validate the correctness of the present method.Finally,some consolidation properties of the problem were analyzed.Comparison of the average degree of consolidation defined by pore pressure with that defined by settlement shows that they are different and the maximum difference is 22.8%.The influences of parameters of Merchant model and the rate of the water level on the consolidation are great.The smaller the viscosity coefficient is,the later the rate of consolidation decreases.The rate of consolidation is decreased with the decrease of the rate of the water level fall.Therefore,the lagged effect of land subsidence should be considered in the actual project.

Withdrawal time in excellent or very poor bowel preparation qualities

AIM: To evaluate association(s) between withdrawal time and polyp detection in various bowel preparation qualities. METHODS: Retrospective cohort analysis of screening colonoscopies performed between January 2005 and June 2011 for patients with average risk of colorectal cancer. Exclusion criteria included patients with a personal history of adenomatous polyps or colon cancer, prior colonic resection, significant family history of colorectal cancer, screening colonoscopy after other abnormal screening tests such as flexible sigmoidoscopy or barium enema, and screening colonoscopies during in-patient care. All procedures were performed or directly supervised by gastroenterologists. Main measurements were number of colonic segments with polyps and total number of colonic polyps.RESULTS: Multivariate analysis of 8331 colonosco-pies showed longer withdrawal time was associated with more colonic segments with polyps in good(adjusted OR = 1.16; 95%CI: 1.13-1.19), fair(OR = 1.13; 95%CI: 1.10-1.17), and poor(OR = 1.18; 95%CI: 1.11-1.26) bowel preparation qualities. A higher number of total polyps was associated with longer withdrawal time in good(OR = 1.15; 95%CI: 1.13-1.18), fair(OR = 1.13; 95%CI: 1.10-1.16), and poor(OR = 1.20; 95%CI: 1.13-1.29) bowel preparation qualities. Longer withdrawal time was not associated with more colonic segments with polyps or greater number of colonic polyps in bowel preparations with excellent(OR = 1.07, 95%CI: 0.99-1.26; OR = 1.11, 95%CI: 0.99-1.24, respectively) and very poor(OR = 1.02, 95%CI: 0.99-1.12; OR = 1.05, 95%CI: 0.99-1.10, respectively) qualities.CONCLUSION: Longer withdrawal time is not associated with higher polyp number detected in colonoscopies with excellent or very poor bowel preparation quality.

Effect of testosterone on morphine withdrawal syndrome in rats

Aim： To determine whether testosterone is involved in morphine withdrawal syndrome （WS）. Methods： In order to induce dependency, rats were treated with subcutaneous injection of morphine （days 1-2, 5 mg/kg; days 3-5, 7.5 mg/kg; days 6-8, 10 mg/kg）, and after the last dose of morphine （day 8） WS was induced by intraperitoneal injection of naloxone （1 mg/kg）. Wet dog shake （WDS）, abdomen writhing （AW）, and jumps （J） were recorded as indicators of WS. Results： The severity of WDS, AW, and J in male rats was greater than that in females. Accordingly, in 4-week castrated and flutamide-treated （10 mg/kg/day for 8 days, i.p.） male rats, WDS, AW, and J were significantly decreased compared to male control rats. Testosterone replacement therapy （10 mg/kg/day for 8 days, i.m.） in 4-week castrated rats restored the severity of WDS, AW, and J behaviors to the level of non-castrated male rats, whereas testosterone potentiated the WDS behavior in non-castrated male rats. Conclusion： It can be concluded that testosterone might be effectively involved in morphine WS.

Effect of withdrawal rate on microstructure of a hypoeutectic Al-Si alloy by low superheat DC casting

To obtain the billet with homogeneous and spheroidized primary grains is the key step in the semi-solid forming process. Among the semi-solid billet preparation methods, the process of low-superheat direct chill (DC) casting is simpler and more effective. In this study, the billets of AlSi7Mg alloy were prepared by low-superheat DC casting at various withdrawal rates. The effect of withdrawal rate on the surface quality of the billets was investigated, and the evolution mechanism of the microstructural morphology in the billets was analyzed. The results show that the periodic corrugations and a large quantity of fine shrinkage pits appear in the billet surface when the withdrawal rate is 100 mm·min-1, and the above defects in the billet surface can be eliminated completely when the withdrawal rate is above 150 mm·min-1. But when the withdrawal rate is too fast (250 mm·min-1), the primary α grains, except the ones in the billet center, have not enough time for ripening due to the high silidification rate, and will solidify as the dendrite structure. When the withdrawal rate is between 150 - 200 mm·min-1, the dendritic growth of the primary α grains is effectively inhibited, and a billet of AlSi7Mg alloy with a smooth surface and homogeneous, fine, non-dendritic grains can be obtained.

Protective effect of Ocimum sanctum Linn. leaf extract on ethanol withdrawal syndrome in Wistar rats

Objective: To evaluate the effects of Oscimum sanctum L(O. sanctum), an important medicinal herb, on alcohol withdrawal syndrome in Wistar rats. Methods: Liquid diet with 7.2%, v/v ethanol was administered to the rats for 21 d. Control group animals received sucrose as an isocaloric liquid diet. After alcohol withdrawal, rats were examined at 6 th and 24 th hour for major withdrawal signs that included anxiety and hyper locomotor activity. Ethanol withdrawal anxiety was tested using elevated plus maze, light and dark model; the hyper locomotor activity using actophotometer. O. sanctum leaf extract(100, 200 and 300 mg/kg, oral) and diazepam(2 mg/kg, i.p) were administered to the treatment group animals 30 min before alcohol withdrawal estimation. Drug treatment was also given 30 min before the second observation at 24 th hour. On the last day of the protocol, rats were sacrificed by cervical dislocation liver, kidney and brain were isolated and preserved in formalin for further histopathological examination. Results: Findings from the present study revealed that O. Sanctum leaf extract treatment at doses 100, 200 and 300 mg/kg, oral had a significant protective effect on signs and symptoms of ethanol withdrawal in alcohol-dependent rats. However, no remarkable pathological and microscopic alterations were observed in histopathological examination. Conclusions: O. sanctum seems to be an active drug for the treatment of alcohol abstinence syndrome.

Overhead Concentration Platform of Total Withdrawal Operation in Cyclic Total Reflux Batch Distillation

The total withdrawal operation is an inevitable section in cyclic total reflux batch distillation.In the operation,an interesting phenomenon "overhead concentration platform"(OCP) appears,which is defined as a period of time with high overhead concentrations when the operation is changed from total reflux to total withdrawal.The OCP phenomenon and its influential factors,such as the theoretical stage number,feed concentration,and feed composition,are examined by simulations and experiments.The experimental equipment is a column with random packings.It is shown that the number of theoretical stages influences the OCP more significantly than the other factors.

Clinical study of early steroid withdrawal after liver transplantation

To study steroid withdrawal in immunosuppresion after liver transplantation (LTx).Methods Fifty-eight consecutive patients undergoing primary LTx,under cyclosporine and steroid immunosuppresion,10 additional patients treated with mycophemolate mofetil (MMF),were included in this study.If there was no evidence of rejection and the patient’s liver function tests were nearly normal,the steroid weaning process started 2 to 3 weeks after LTx.Results During a mean follow-up period of 9.3±5.5 months after LTx,54 patients survived and 4 died.Steroids could be withdrawn in 72.2% patients at 3rd month post-transplant,in 76.2% at 6th month and in 77.8% at first year,respectively.In 3 patients with rejection after steroid withdrawal,the steroid dose before withdrawal was given.After the rejection was reversed the steroid was withdrawn.Freedom from steroids was thus observed in 10 additional patients treated with MMF at 3rd to 4th month post-transplant.Conclusion Cyclosporine-based immunosuppression allows safe early steroid withdrawal in some patients of LTx.3 refs,1 tab.

Sidiming attenuates morphine withdrawal syndrome and nitric oxide (synthase) levels in morphine-dependent rats and rhesus monkeys

The present study analyzed the effects of Sidiming, a Chinese herbal compound, on withdrawal syndrome, body weight loss, and serum levels of nitric oxide and its synthase in morphine- dependent rats and rhesus monkeys. These effects were compared with clonidine, an active control drug used for clinical treatment. Results showed that 4 and 8 g/kg Sidiming, respectively, significantly suppressed morphine withdrawal syndrome and reduced body mass loss in morphine-dependent rats. In addition, 2.4 and 4.8 g/kg Sidiming, respectively, significantly attenuated withdrawal syndrome in rhesus monkeys. High-dose Sidiming （8 g/kg in rats and 4.8 g/kg in rhesus monkeys） led to significantly inhibited serum levels of nitric oxide and its synthase in morphine-dependent rats and rhesus monkeys, which were greater than clonidine. These findings suggested that Sidiming treatment attenuated withdrawal syndrome in morphine-dependent rats and rhesus monkeys by inhibiting serum nitric oxide and its synthase.

Dependency of microstructure and microhardness on withdrawal rate of Ti-43Al-2Cr-2Nb alloy prepared by electromagnetic cold crucible directional solidification

The intermetallic Ti-43Al-2Cr-2Nb(at.%) alloy was directionally solidified in an electromagnetic cold crucible with different withdrawal rates(V) ranging from 0.2 to 1.0 mm·min^(-1), at a constant temperature gradients(G=18 K·mm^(-1)). Macrostructures of the alloy were observed by optical microscopy. Microstructures of the alloy were characterized by scanning electron microscopy(SEM) in back-scattered electron mode and transmission electron microscopy. Results showed that morphologies of macrostructure depend greatly on the applied withdrawal rate. Continuous columnar grains can be obtained under slow withdrawal rates ranging from 0.2 to 0.6 mm·min^(-1). The microstructure of the alloy was composed of α_2/γ lamellar structures and a small number of mixtures of B2 phases and blocky γ phases. The columnar grain size(d) and interlamellar spacing(λ) decrease with an increasing withdrawal rate. The effect of withdrawal rate on microhardness was also investigated. The microhardness of the directional y solidified Ti-43Al-2Cr-2Nb alloy increases with an increase in withdrawal rate. This is mainly attributed to the increase of B2 and α_2 phases as well as the refinement of lamellae.