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The larvae of Echinococcus (hydatidcyst) can parasitize humans and animals, causing a serious zoonotic disease-echinococcosis. The life history of Echinococcus is complicated, and as the disease progresses slowly after infection, early diagnosis is difficult to establish. Due to the limitations of imaging and immunological diagnosis in this respect, domestic and foreign scholars have established a variety of molecular detection techniques for the pathogen Echinococcus over recent years, mainly including nested polymerase chain reaction (PCR), multiplex PCR, real-time quantitative PCR, and nucleic acid isothermal amplification technology. In this article, the research progress of molecular detection technology for Echinococcus infection currently was reviewed and the significance of these methods in the detection and diagnosis of hydatid and hydatid diseases was also discussed.

We report on ten-stage interband cascade light-emitting diodes (ICLEDs) using an InAs/GaAsSb superlattices active region with a peak emission wavelength of 4.9 μm at the temperature of 80 K. The ICLED devices integrated with an immersion lens achieve a wall-plug quantum efficiency of 6.6% and an emittance of 1.9 W/cm2 under 80 K and 7.7 A/cm2, which is seven times larger than the basic device without the immersion lens. We present a detailed analysis of the recombination rates and their relationship with the quantum efficiency. The Shockley–Read–Hall and Auger recombination rates were measured using carrier-density dependent time-resolved photoluminescence spectra. The band structure of InAs/GaAsSb superlattices is calculated to study their relationship with the Auger recombination rates.

The data of clinical characteristics, medical cost and prognosis of 22 anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis children from the Department of Neurology, Capital Institute of Pediatrics between May 2018 and January 2021 were analyzed, and 6 of them occurred paroxysmal sympathetic hyperactivity syndrome (PSH). It was found that the anti-NMDAR encephalitis children with PSH had severer consciousness disorder [median Glasgow Coma Scale (GCS) score at admission: 7.5], longer duration of consciousness disorder (median time: 53 days), higher hospitalization cost (median cost: 230 000 RMB), severer neurological injury at onset [median modified Rankin Scale (mRS) score at admission: 4], and longer recovery time of neurological function (median time of mRS score recovered to 0-2: 7 months), compared with those without PSH (all分析了2018年5月至2021年1月首都儿科研究所附属儿童医院神经内科收治的22例抗N-甲基-D-天冬氨酸受体（NMDAR）脑炎中，6例伴发交感神经过度兴奋综合征（PSH）患儿的临床特征、花费及预后，发现伴PSH的抗NMDAR脑炎意识障碍重（入院时GCS中位评分7.5分）、意识障碍持续时间长（中位天数53 d）、住院花费高（中位花费23.0万元）、起病时神经功能损伤重（入院时mRS中位分数4分）、神经功能恢复时间长（mRS恢复至0~2分，中位时间7个月），与不伴PSH的抗NMDAR脑炎患儿比较差异均有统计学意义（

To construct a cDNA library ofTotal RNA was extracted fromThe SMATR cDNA library ofA SMART cDNA library of

本文报道首都儿科研究所附属儿童医院收治的1例颈深部脓肿患儿的诊疗经过。患儿女，2岁，家长诉“睡眠增多5 d，头痛伴发热4 d”，初诊于神经内科，后经专科查体及影像学检查确诊为颈深部脓肿后转入耳鼻喉科治疗。予经咽后壁脓肿穿刺引流手术联合敏感抗生素抗感染治疗后患儿痊愈出院。儿童颈深部感染有时早期临床表现不典型，易漏诊或误诊。.

To investigate the prevalence and risk factors ofA cross-sectional questionnaire survey was conducted among AIDS patients in Nanchang City during the period between May and September, 2016.A survey was conducted in Nanchang City from May to September 2016. A total of 505 AIDS patients were investigated, and the prevalence ofThe prevalence of

To investigate the prevalence and risk factors ofA cross-sectional questionnaire survey was conducted among students sampled from a primary school in Jiangjin District, Chongqing City on April, 2018, and their stool samples were collected for microscopic examinations,A total of 466 primary students were surveyed, and the subjects had a mean age of (9.81±1.66) years and included 236 males (50.64%) and 230 females (49.36%). The prevalence ofThere is a high prevalence of

IgE型多发性骨髓瘤非常罕见，预后不良。本文结合文献复习报告一例IgE-κ型多发性骨髓瘤诊断及治疗过程，通过规范治疗，获得了较好反应。.

Endoplasmic reticulum (ER) stress has an effect on cancer cell proliferation and survival. TMTC1 has been reported to be involved in cell proliferation and inflammation, and development of ER. Hsa_circRNA_101036 is an exon circRNA formed by splicing of TMTC1 mRNA precursor. This study intends to explore the effect of hsa_circRNA_101036 on the malignant behavior of oral squamous cell carcinoma through endoplasmic reticulum stress.We firstly evaluated the levels of Hsa_circRNA_101036 in human oral mucous fibroblasts (hOMF), and in several OSCC cell lines, including FaDu, OECM1, SAS, HSC3. Then, we studied the effects of overexpression of Hsa_circRNA_101036 on the cell proliferation, apoptosis, invasion, migration, and cytokine release in OSCC cells. Finally, we evaluated the levels of CHOP that are critical in ER and the ROS levels in OSCC cells.We found that compared with hOMF, a significantly lower mRNA expression of Hsa_circRNA_101036 was found in OECM1 and HSC3 cells. In OECM1 and HSC3 cells, with overexpression of Hsa_circRNA_101036, a significant decrease in cell proliferation, apoptosis, invasion, migration, and cytokine release was found. A significantly increased ROS, as well as increased protein level of CHOP, P38 and Bcl-2, was found in cells with Hsa_circRNA_101036 overexpression.This study indicated that Hsa_circRNA_101036 may acts as a tumor suppressor in OSCC via regulating the ER in cancer cells.

Glioma is a malignant brain cancer capable of spreading to the microenvironment. Long non-coding RNA (lncRNA) X inactive specific transcript (XIST) was recognized as a significant regulator in many cancers. However, the molecular mechanism of XIST in glioma cell radio-sensitivity requires further exploration.The expression of XIST, microRNA (miR)-329-3p and cyclic AMP response element-binding protein 1 (CREB1) was evaluated by quantitative Real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry, respectively. Transwell assay was performed to detect cell invasion. Protein expression of gamma-H2AX (γ-H2AX) and CREB1 was determined by Western blot. The correlation between miR-329-3p and XIST or CREB1 was determined by dual-luciferase reporter assay. Animal models were established by subcutaneously injecting U251 cells transfected with sh-XIST and sh-NC.XIST and CREB1 were overexpressed whereas miR-329-3p was low-expressed in glioma tumors and cells compared with the normal counterparts. XIST knockdown inhibited cell proliferation, invasion and induced cell apoptosis by enhancing cell sensitivity to X-ray radiation in glioma. Then, we discovered that miR-329-3p directly interacted with XIST or CREB1 in glioma. In addition, miR-329-3p inhibitor abolished XIST silencing-induced regulatory effects on cell proliferation, apoptosis, invasion, and radio-sensitivity. Meanwhile, miR-329-3p inhibitor counteracted CREB1 silencing-induced inhibition on cell progression and facilitation on radio-sensitivity in glioma. Moreover, we found that XIST could increase CREB1 expression by sponging miR-329-3p. Animal experiments revealed that XIST silencing restrained tumor growth in vivo.XIST accelerates cell proliferation, invasion and inhibits cell apoptosis by repressing radio-sensitivity of glioma via enhancing CREB1 expression through sponging miR-329-3p, representing prospective methods for glioma treatment.

Owing to load variations, the power tracking of fuel cells in automotive applications is emphasized. We address the control strategies to meet varying power demands while optimizing system efficiency. Based on the control-oriented proton exchange membrane fuel cell model, the relative gain array is analyzed to determine variable parings in control design. As the dynamics of two control variables are different, a cascade control architecture is adopted. A feedforward-feedback composite control is used to achieve fast response and eliminate the stable error. To avoid oxygen starvation at power transients, an oxygen excess ratio constrained strategy is proposed to limit the load current if there is lack of reaction oxygen. A mixed-sensitivity synthesis is applied to suppress parameter perturbation and improve system robustness. To further suppress the fluctuations of the oxygen excess ratio and achieve the maximum system efficiency, an oxygen excess ratio invariant strategy is developed, which coordinates load current with airflow. A comparative study is conducted, with two scenarios of power tracking and fuel cell degradation. The results show that the mixed-sensitivity strategy has a fast response in power tracking and effective perturbation suppression performance, while the oxygen excess ratio invariant strategy maximizes the system efficiency.

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This study tries to compare three methods in complex abdominal wall reconstruction.A retrospective review was conducted at a single medical center between December 2008 and May 2019. Forty-seven patients who received abdominal fascia repair were enrolled. The patients were divided into three groups: A [component separation technique (CST)], B (partition technique), and C [extended anterolateral thigh (ALT) flap]. All relevant patient information was collected. Statistical analysis including one-way analysis of variance, Chi-square test, and the receiver operating characteristic curve were used.There were no significant differences between the group results related to gender, age, BMI, follow-up, diabetes mellitus, tobacco, or short-, and long-term complications. However, there were significant differences in fascia defect size between groups (group A: 7.6 cm vs. group B: 10.76 cm vs. group C: 13.64 cm). The averaged operative time in group C (339.25 mins) was significantly longer than that in group A (145.40 mins) and B (152.37 mins). The hospitalization in group C (24.1 days) was significantly longer than that in group A (8.2 days) and B (10.3 days). The complication thresholds of group A and group B are 9.45 cm and 11.75 cm, respectively.This study suggests that extended ALT flap provides the largest fascia defect closure, followed orderly by partition technique and CST, but requires longer operative time and hospitalization. There are no significant differences in postoperative complications between three groups. A prospective study with indications based on these findings is suggested.

To investigate the prevalence and risk factors ofA cross-sectional study was conducted in Fuyang City, Anhui Province in 2016. The demographic and socioeconomic status, and the lifestyle and production style were collected using a questionnaire survey.A total of 398 HIV/AIDS patients were enrolled in this study, with a mean age of 49.3 years, a mean body weight of 55.9 kg and a mean height of 164.4 cm. The prevalence ofThe prevalence of

Motivated by the successful application of discriminative dictionary learning, a new idea can be provided to the classifier for radar signal recognition. Based on the Fisher discriminative dictionary learning, a method of radar signal recognition is proposed by integrating feature extraction and dictionary learning. Firstly, 1/2 bispectra diagonal slice has been taken advantage of reducing the data dimension. Then, the sub-dictionary of each sort of signal can be trained by introducing Fisher criterion to make the dictionary more discriminative. At the same time, the reconstruction error and sparse coding coefficients are considered by discrimination criterion, so the classification of the objective function with reconstruction error and similarity of sparse coding coefficients has better discriminative performance. The simulation shows that comparing among the other four algorithms, the proposed method has more robust and the recognition rate improves 7.05% on average.

Accurate evaluation of transmission line model at high frequencies for characterizing field-to-wire coupling of coated twisted wire pair (TWP) with a grounded conductor is performed in this paper. We derive the main steps to solve the TWP problem. Further, such coated TWP with a ground conductor is simulated for different geometrical parameters of the TWP, and different incident wave frequencies, directions and polarization angles. In particular, the approximation condition of TLM model is examined in detail, and most results calculated by the TLM model are beyond 1GHz but below 5GHz. The captured common mode and differential mode currents are compared with that of commercial software FEKO, but the cost for TLM model simulation is very low.

We present a multichannel continuous-wave (CW) fiber cavity ringdown (FCRD) gas sensing method based on frequency-shifted interferometry (FSI). This scheme detects gas concentration by measuring the intensity decay rates of continuous light from different ringdown cavities in the spatial domain, unlike conventional FCRD techniques, which measure the decay rates of pulse light in the time domain. This method shares one CW light source, one slow detector, and one slow data collector. In order to illustrate the theory, acetylene gas concentration measurement in a two-channel FSI-FCRD system was experimentally conducted in the range of 0%-1%. A linear relation was established between concentration and absorption loss, which is proportional to the intensity decay rate, and the measurement resolutions of 3.871%/dB and 3.658%/dB were achieved, respectively. The results reveal that the proposed system has the advantages of low cost, high sensitivity, high precision, and good stability in multichannel gas detection.

To investigate the protective effect of intermedin1-53 (IMD1-53) on cardiac function in rats with septic shock and its underlying mechanism.Twenty-four male Sprague-Dawley (SD) rats were randomly assigned into three groups, namely the control group (NC group), septic shock group (ET group) and IMD1-53 treatment group (IMD group), with 8 rats in each group. Levels of hemodynamic indicators, blood glucose, lactate acid, CK-MB (creatine kinase-MB) and cTnI (cardiac troponin I) in rats were determined. Cardiac tissues of rats were collected for TUNEL (terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling) staining. Protein levels of caspase-3, caspase-9, Bax, Bcl2, iNOS (inducible nitric oxide synthase) and COX-2 (cyclooxygenase-2) in cardiac tissues were detected by Western blot. Moreover, activities of SOD (superoxide dismutase), CAT (catalase) and MDA (malondialdehyde) in myocardial homogenate were determined, thereby exploring the effect of IMD1-53 on oxidative stress and cardiomyocyte apoptosis in rats with septic shock induced by endotoxin.Lower levels of mean arterial blood pressure (MABP), maximum rate of left ventricular diastolic pressure (+LVdp/dtmax) and left ventricular systolic pressure (LVSP) were observed in ET group than those of NC group (p0.05). Levels of lactic acid, blood glucose, CK-MB and cTnI in ET group were remarkably increased than those of NC group (p0.05). Moreover, activities of SOD and CAT in myocardial homogenate of ET group were remarkably reduced in comparison with those of NC group (p0.05). Protein levels of caspase-3, caspase-9, Bcl-2, Bax, iNOS and COX-2 in ET group were all remarkably elevated than those of NC group (p0.05). The above indicators were all significantly improved in IMD group than those of ET group (p0 05).IMD1-53 can protect cardiac function in rats with septic shock via inhibiting oxidative stress and cardiomyocyte apoptosis.

In this study, second-harmonic imaging microscopy was used to monitor precancerous colorectal lesions at different stages. It was found that the morphology of glands and lamina propria in mucosa changes with the progression of colorectal diseases from normal to low-grade intraepithelial neoplasia to high-grade intraepithelial neoplasia and this microscopy has the ability of direct visualization of these warning symptoms. Furthermore, two morphologic variables were quantified to determine the changes of glands and collagen in lamina propria during the development of colorectal intraepithelial neoplasia. These results suggest that second-harmonic imaging microscopy has the potential in label-freely and effectively distinguishing between normal and precancerous colorectal tissues, and will be helpful for early diagnosis and treatment of colorectal diseases.

To investigate the influence of deposition pressure on the texture of pyrolytic graphite, a series of experiments were carried out. The pyrolytic graphites were fabricated at 2000°C with propylene as the carbon source and nitrogen as the carrier gas in a system pressure from 1·1 to 1·8 kPa. Results show that lowering the deposition pressure will increase the density and thin the growth cones. The reduce of deposition pressure will also cause an increasing in the degree of graphitisation extracted from X-ray diffraction patterns and the value of (IG/ID) in Raman spectra. Therefore, lower deposition pressure is more inclined to yield high texture pyrolytic graphite. Finally, the deposition mechanism was discussed.

Polycrystalline BiFeO3 films were fabricated by radio frequency magnetron sputtering using a Bi1.1FeO3 target onto the glass and Si/SiO2/Ti/Pt substrates respectively. The samples which were annealed with different annealing conditions are pure without impurities. Our results indicate that there are relatively wider growth conditions for pure polycrystalline BFO phases.

Due to the low temperature of LNG (liquefied natural gas), there is abundant cold energy can be utilized during the regasification process. Therefore a novel hybrid solar-LNG cold energy recovery system was proposed. In this system, LNG cold energy is used as a heat sink for a propane Rankine power cycle and a cascaded ethylene glycol refrigeration cycle. Then through a direct expanding combined with the preheating of solar thermal energy, more power is generated by the regasified LNG. A thermodynamic analysis was carried out to investigate the best system design. Meanwhile, the influences of some key operating parameters on net output power and exergy efficiency were investigated. The results show that higher inlet temperature and pressure of NTB (natural gas turbine) are beneficial to system performance.

Characteristics of metal–oxide–high-k–oxide–silicon (MOHOS) memories with oxygen-rich or oxygen-deficient GdO as charge storage layer annealed by NH3 or N2 are investigated. Transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction are used to analyze the cross-sectional quality, composition and crystallinity, respectively, of the stacked gate dielectric with a structure of Al/Al2O3/GdO/SiO2/Si. The MOHOS capacitor with oxygen-rich GdO annealed in NH3 exhibits a good trade-off among its memory properties: large memory window (4.8 V at ±12 V, 1 s), high programming speed (2.6 V at ±12 V/100 μs), good endurance and retention properties (window degradation of 5 % after 105 program/erase cycles and charge loss of 18.6 % at 85 °C after 10 years, respectively) due to passivation of oxygen vacancies, generation of deep-level traps in the grain boundaries of the GdO layer and suppression of the interlayer between GdO and SiO2 by the NH3 annealing.

Contains fulltext : 193179.pdf (Publisher’s version ) (Open Access) The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.

The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column. Neurons with various sizes were identified in grey matter by dark spots of nonfluorescent nuclei encircled by cytoplasm-emitting two-photon excited fluorescence signals. Nerve fibres and neuroglias were observed in white matter. Besides, the spinal arteries were clearly presented by NLO microscopy. Using spectral and morphological information, this technique was proved to be an effective tool for label-freely imaging spinal cord tissues, based on endogenous signals in biological tissue. With future development, we foresee promising applications of the NLO technique for in vivo, real-time assessment of spinal cord diseases or injures.

Colon cancer (CC) is the third most common malignancy with high mortality rate in the world. The impacts of metastasis associated in colon cancer 1 (MACC1) on growth and metastasis processes of CC were investigated by overexpression and interference lentivirus infection.Firstly, overexpression and interference plasmids were constructed with GV115 vector and lentivirus were packaged using 293T cells. Human CC cell lines SW1116 and HCT116 were used and divided into four groups respectively, namely control group, blank group, MACC1 siRNA group (infected with interference lentivirus) and MACC1 group (infected with overexpression lentivirus). Then, cell proliferation and clone formation were examined. Besides, migration and invasion of cells were investigated by wound healing and transwell assays, respectively. Additionally, liver metastasis was evaluated in nude xenografts model.Overexpression and interference lentivirus of MACC1 were successfully constructed. After infected with overexpression lentivirus, cell proliferation, clone formation number, cell invasion and migration capabilities of CC cells were significantly increased (p0.05). Furthermore, decreased cell proliferation, smaller and fewer clones, as well as weakened cell migratory and invasive capabilities were observed in SW1116 and HCT116 cells treated with interference lentivirus of MACC1 (p0.05). Additionally, liver metastasis rate was higher in SW1116 cells with a higher expression level of MACC1 than that in HCT116 cells with a lower MACC1 expression level.MACC1 promotes the growth and metastasis processes of CC cells.

Glioblastoma multiforme (GBM-WHO grade IV) is the most common and the most aggressive form of brain tumors in adults with the median survival of 10-12 months. The diagnostic detection of extracellular matrix (ECM) component in the tumour microenvironment is of prognostic value. In this paper, the fibrillar collagen deposition associated with vascular elements in GBM were investigated in the fresh specimens and unstained histological slices by using multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG). Our study revealed the existence of fibrillar collagen deposition in the adventitia of remodelled large blood vessels and in glomeruloid vascular structures in GBM. The degree of fibrillar collagen deposition can be quantitatively evaluated by measuring the adventitial thickness of blood vessels or calculating the ratio of SHG pixel to the whole pixel of glomeruloid vascular structure in MPM images. These results indicated that MPM can not only be employed to perform a retrospective study in unstained histological slices but also has the potential to apply for in vivo brain imaging to understand correlations between malignancy of gliomas and fibrillar collagen deposition.

In this study, we exposed black sea bream, Mylio macrocephalus (Basilewsky), fibroblast (BSF) and silver sea bream, Sparus sarba Forsskål, fibroblast (SSF) cell lines to a recombinant Vibrio harveyi haemolysin (VHH) and investigated mechanisms involved in apoptosis. A decrease in mitochondrial membrane potential, followed by an increase in caspase 3 activity, occurred within 2-8 h of VHH exposure, in both cell lines; however, VHH did not alter cellular levels of reactive oxygen species. As heat shock protein 70 (HSP70) is known to prevent the onset of apoptosis in certain mammalian cells, we aimed to test whether such a protective effect is operative in VHH-exposed fibroblasts. The amounts of HSP70 were elevated in SSF and BSF via an acute heat shock or an acute heat shock followed by a 6 h recovery. It was found that the VHH-mediated reduction in mitochondrial membrane potential was suppressed in cells that had a 6 h post-heat shock recovery, and the protective effect of heat shock-induced HSP70 was attenuated following treatment of cells with the HSP70 inhibitor, quercetin. This study demonstrates how haemolysin causes cell death via induction of apoptosis and provides evidence as to the role of HSP70 as an anti-apoptotic factor.

In this study, we exposed black sea bream, Mylio macrocephalus (Basilewsky), fibroblast (BSF) and silver sea bream, Sparus sarba Forsskal, fibroblast (SSF) cell lines to a recombinant Vibrio harveyi haemolysin (VHH) and investigated mechanisms involved in apoptosis. A decrease in mitochondrial membrane potential, followed by an increase in caspase 3 activity, occurred within 2-8 h of VHH exposure, in both cell lines; however, VHH did not alter cellular levels of reactive oxygen species. As heat shock protein 70 (HSP70) is known to prevent the onset of apoptosis in certain mammalian cells, we aimed to test whether such a protective effect is operative in VHH-exposed fibroblasts. The amounts of HSP70 were elevated in SSF and BSF via an acute heat shock or an acute heat shock followed by a 6 h recovery. It was found that the VHH-mediated reduction in mitochondrial membrane potential was suppressed in cells that had a 6 h post-heat shock recovery, and the protective effect of heat shock-induced HSP70 was attenuated following treatment of cells with the HSP70 inhibitor, quercetin. This study demonstrates how haemolysin causes cell death via induction of apoptosis and provides evidence as to the role of HSP70 as an anti-apoptotic factor.

Due to the rapid onset of resistance to most antibacterial drugs, research efforts are focusing on new classes of antibacterials with different mechanisms of action from clinically used antibacterials. Pleuromutilin derivatives have received more and more scientific attention for their unique mechanism of action. Two pleuromutilin derivatives, tiamulin and valnemulin have been successfully developed as antibiotics for veterinary use. Retapamulin, another pleuromutilin derivative has been approved for use in humans in April 2007 by Food and Drug Administration (FDA). It has been shown that there is rarely cross-resistance between pleuromutilin derivatives and other antimicrobial agents, and the development of resistance bacterial is still low. This review will demonstrate mechanism of action of pleuromutilin derivatives and reveal the structure-activity relationship (SAR) of pleuromutilin derivatives. Additionally, the pleuromutilin antibacterial derivative agents in the market, such as tiamulin, valnemulin and retapamulin, will be discussed. It is proposed that new antibacterial agents might be developed from pleuromutilin derivatives in the future.