Improving temperature characteristics of GaN-based ultraviolet laser diodes by using InGaN/AlGaN quantum wells.

Temperature characteristics of GaN-based laser diodes are investigated. It is noted that the characteristic temperature of the threshold current (T0) decreases with decreasing lasing wavelength for GaN-based LDs. The performance deteriorates seriously for UV LDs at high temperature. It is ascribed to the increase of carriers escaping from quantum wells due to the lower potential barrier height. In this Letter, AlGaN is used as the barrier layer in UV LDs instead of GaN to improve the temperature characteristic of the threshold current and slope efficiency by increasing the potential barrier height of quantum wells. Based on this structure, a high output power of 4.6 W is obtained at the injection current of 3.8 A; its lasing wavelength is 386.8 nm.

Mesoporous silica nanoparticles with chiral pattern topological structure function as "antiskid tires" on the intestinal mucosa to facilitate oral drugs delivery.

The weak adhesion between nanocarriers and the intestinal mucosa was one of the main reasons caused the failure in oral delivery. Inspired by the "antiskid tires" with complex chiral patterns, mesoporous silica nanoparticles AT-R@CMSN exhibiting geometrical chiral structure were designed to improve the surface/interface roughness in nanoscale, and employed as the hosting system for insoluble drugs nimesulide (NMS) and ibuprofen (IBU). Once performing the delivery tasks, AT-R@CMSN with rigid skeleton protected the loaded drug and reduced the irritation of drug on gastrointestinal tract (GIT), while their porous structure deprived drug crystal and improved drug release. More importantly, AT-R@CMSN functioned as "antiskid tire" to produce higher friction on intestinal mucosa and substantively influenced multiple biological processes, including "contact", "adhesion", "retention", "permeation" and "uptake", compared to the achiral S@MSN, thereby improving the oral adsorption effectiveness of such drug delivery systems. By engineering AT-R@CMSN to overcome the stability, solubility and permeability bottlenecks of drugs, orally administered NMS or IBU loaded AT-R@CMSN could achieve higher relative bioavailability (705.95% and 444.42%, respectively) and stronger anti-inflammation effect. In addition, AT-R@CMSN displayed favorable biocompatibility and biodegradability. Undoubtedly, the present finding helped to understand the oral adsorption process of nanocarriers, and provided novel insights into the rational design of nanocarriers.

Room temperature continuous-wave operated 2.0-W GaN-based ultraviolet laser diodes.

Temperature characteristics of near-UV laser diodes (LDs) with a lasing wavelength of 384 nm are investigated. The characteristic temperature of threshold current (T0) of the UV LDs is low. Thus, the performance of the UV LDs under continuous wave (CW) operation is not as good as under pulsed operation especially at a high injection current. In addition, it is found that self-heating is a key factor for CW characteristics of the UV LDs, where suppression of the self-heating by using thick waveguide layers can increase the critical current of thermal rollover of the UV LD's operation. A high CW output power of 2.0 W is achieved for an InGaN near-UV LD with the n-side down on a sub-mount, whose threshold current density is 1.27 kA/cm2 and the highest wall plug efficiency (WPE) is approximately 15.9% at an injection current of 1.2 A.

Comparative effect of ciprofloxacin and moxifloxacin on the modulation of bile acid profiles and gut microbiota in rats

Abstract Fluoroquinolones are an important class of antimicrobial agents to manage infectious diseases. However, knowledge about how host bile acids are modified by fluoroquinolones is limited. We investigated and compared the impact of fluoroquinolones on circulating bile acid profiles and gut microbiota from in vivo studies. We administered ciprofloxacin (100 mg/kg/day) or moxifloxacin (40 mg/kg/day) orally to male Wistar rats for seven days. Fifteen bile acids (BAs) from the serum and large intestine were quantified by HPLC-MS/MS. The diversity of gut microbiota after ciprofloxacin and moxifloxacin treatment was analyzed using high-throughput, next-generation sequencing technology. The two fluoroquinolone-treated groups had different BA profiles. Ciprofloxacin significantly reduced the hydrophobicity index of the BA pool, reduced secondary BAs, and increased taurine-conjugated primary BAs in both the serum and large intestine as compared with moxifloxacin. Besides, ciprofloxacin treatment altered intestinal microbiota with a remarkable increase in Firmicutes to Bacteroidetes ratio, while moxifloxacin exerted no effect. What we found suggests that different fluoroquinolones have a distinct effect on the host BAs metabolism and intestinal bacteria, and therefore provide guidance on the selection of fluoroquinolones to treat infectious diseases.

Advances in Basic Studies on Antitumor Effect and Underlying Molecular Mechanisms of Sinomenine / 中国实验方剂学杂志

Tumors are new organisms formed by uncontrollable cell proliferation of local tissues driven by various oncogenic factors. The cause of tumors is unknown with life-threating outcome. Tumors can be classified into benign tumors， borderline tumors， and malignant tumors according to their pathological properties. Among them， malignant tumor is commonly known as cancer， with no specific medicines or reliable cure means， so this is a hot spot and difficult point in current medical research. In ancient literatures， there are many records about the efficacy of Chinese herbal medicine in treating tumor， and modern pharmacological researches have shown that more and more active ingredients of traditional Chinese medicine（TCM） have gradually highlighted their inhibitory effect on various types of tumor. Caulis sinomenii has been used for treatment of rheumatic diseases in TCM for a long history. Sinomenine is a major bioactive alkaloid presented in C. sinomenii， which has demonstrated a wide range of pharmacological activities such as anti-inflammation， immunosuppression， analgesia and sedation， and due to its slightly soluble in water， it is commonly used in clinic in the form of hydrochloride， with its commercial name of Zhengqing Fengtongning. Recent studies show that sinomenine alone or combined with chemoradiotherapy can inhibit growth of several tumors significantly or in a synergistic way， so it is termed as an inhibitor of tumors. Anti-tumor effect of sinomenine involve inhibition of tumor cell proliferation， induction of tumor cell apoptosis， blockade of tumor cell cycle， suppression of tumor invasion and metastasis， induction of autophagy of tumor cells， and reversal of multidrug resistance of tumor cells. Upon combination with nanomaterials， it can enhance efficiency and reduce toxicity. Here we summarized and reviewed recent advances on basic anti-tumor research of sinomenine， and then made a classification and description according to its in vivo and in vitro pharmacological action and mechanism of action， so as to elucidate the great potential of sinomenine as a promising anti-tumor drug， and provide reference for further research on its anti-tumor mechanism.

Mechanical intestinal obstruction due to isolated diffuse venous malformations in the gastrointestinal tract: A case report and review of literature.

BACKGROUND: Isolated gastrointestinal venous malformations (GIVMs) are extremely rare congenital developmental abnormalities of the venous vasculature. Because of their asymptomatic nature, the diagnosis is often quite challenging. However, as symptomatic GIVMs have nonspecific clinical manifestations, misdiagnosis is very common. Here, we report a case of isolated diffuse GIVMs inducing mechanical intestinal obstruction. A literature review was also conducted to summarize clinical features, diagnostic points, treatment selections and differential diagnosis in order that doctors may have a comprehensive understanding of this disease. CASE SUMMARY: A 50-year-old man presented with recurrent painless gastrointestinal bleeding for two months and failure to pass flatus and defecate with nausea and vomiting for ten days. Digital rectal examination found bright red blood and soft nodular masses 3 cm above the anal verge. Computed tomography showed that part of the descending colon and rectosigmoid colon was thickened with phleboliths in the intestinal wall. Colonoscopy exhibited bluish and reddish multinodular submucosal masses and flat submucosal serpentine vessels. Endoscopic ultrasonography showed anechoic cystic spaces within intestinal wall. The lesions were initially thought to be isolated VMs involving part of the descending colon and rectosigmoid colon. Laparoscopic subtotal proctocolectomy, pull-through transection and coloanal anastomosis and ileostomy were performed. Histopathology revealed intact mucosa and dilated, thin-walled blood vessels in the submucosa, muscularis, and serosa involving the entire colorectum. The patient recovered with complete symptomatic relief during the 52-mo follow-up period. CONCLUSION: The diagnosis of isolated GIVMs is challenging. The information presented here is significant for the diagnosis and management of symptoms.

The effect of food intake on the pk of rhein released from diacerein

Diacerein is a symptomatic slow-acting drug used for treating osteoarthritis. This drug is completely metabolized into the active metabolite rhein before reaching the systemic circulation. This study evaluated the effects of food on the pharmacokinetics of rhein released from diacerein in healthy Chinese subjects. This was a single-center, randomized, single-dose, open-label, two-period, cross-over study. Twenty-four healthy subjects were randomly selected to receive a single oral dose of 50 mg diacerein capsule in either fasted or fed state on two separate visits. Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters were calculated using WinNonlin software. In the fasted and fed states, the main pharmacokinetic parameters of diacerein capsule were as follows: Cmax were (4471 ± 936), (3225 ± 755) ng/mL, t1/2 were (4.22 ± 0.42), (4.19 ± 1.05) h, tmax were (2.61 ± 1.25), (3.81 ± 1.29) h, AUC0-24 h were (24223 ± 4895), (24316 ± 5856) h·ng/mL, and AUC0-∞ were (24743 ± 5046), (25170 ± 6415) h·ng/mL. The absorption rate of diacerein capsule was obviously delayed by food intake but the absorption degree remained unaffected.

Pharmacokinetics and safety of repirinast tablets in healthy Chinese subjects

ABSTRACT Repirinast is a new, synthetic, disodium cromoglycate-like antiallergic agent for oral administration in humans. This study evaluated the safety, tolerability and pharmacokinetics of repirinast tablets in healthy Chinese volunteers. This was a phase I, open-label, randomized, single- and multiple-dose study. Subjects were assigned to receive a single dose of repirinast tablet at either 150, 300, or 450 mg, or multiple doses of 150 mg twice daily for 5 days. Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters of active metabolite MY-1250 (deesterified repirinast) were calculated using non-compartmental analysis with WinNonlin software. Statistical analysis was performed using SPSS software. All adverse events (AEs) were mild and of limited duration. No serious adverse event (SAE), death or withdrawal from the study was observed. In the single-dose study, Cmax was reached at about 0.75 hour, and the mean t1/2 was approximately 16.21 hours. Area under curve (AUC) and Cmax increased with dose escalation, but dose proportionality was not observed over the range of 150 to 450 mg. In the multiple-dose study, the steady-state was reached within 3 days with no accumulation. Repirinast tablet was well tolerated in healthy Chinese subjects.

Effects of SMILE and Trans-PRK on corneal higher order aberrations after myopic correction / 国际眼科杂志(Guoji Yanke Zazhi)

·AIM:To observe the effects of small incision lenticule extraction (SMILE) and trans-epithelial photorefractive keratectomy (Trans-PRK) on corneal horizontal coma, vertical coma, and spherical aberration and total higher order aberrations after refractive correction for myopia. ·METHODS: This was a prospective non-randomized cohort study. The cohort included 40 patients (80 eyes) with myopia, who received refraction correction surgery from December 2016 to February 2017 in Leshan Ophthalmic Center. Twenty patients (40 eyes) received SMILE surgery and the other 20 patients (40 eyes) received Trans-PRK surgery. Corneal aberrations were determined by a high-resolution Pentacam Scheimpflug camera before the surgery and at 1 and 3mo after the operation. Statistical analyses were performed using analysis of variance of repeated measures. · RESULTS: At 1 and 3mo post - operation, the uncorrected visual acuity in both groups was better than or equal to the preoperative best corrected visual acuity. The preoperative corneal aberrations showed no significant difference between the two groups (P>0.05). Significantly higher aberration was found after the surgery in both groups (P < 0. 05), however, no significant difference in higher aberration was found between 1 and 3mo post - operation (P > 0. 05). Post - operation, horizontal and vertical coma had no significant difference between the two groups (P>0.05), while SMILE group showed lower spherical aberration and lower total higher order aberration than Trans-PRK group (P<0.05). ·CONCLUSION: Both SMILE and Trans-PRK increase corneal aberration and their effects on horizontal and vertical coma are similar. However, SMILE has a minor influence on spherical aberration and total high order aberration than Trans-PRK.

Effects of Shuangdanmingmu capsule on retinal vascular morphology and VEGF expression in rats with diabetic retinopathy / 国际眼科杂志(Guoji Yanke Zazhi)

Abstract?AlM: To observe the effects of Shuangdanmingmu capsule on VEGF expression and retinal vascular morphology in rats with diabetic retinopathy ( DR) .?METHODS: DR rats were fed with Shuangdanmingmu capsule. By comparing with the normal group, the model control group, and positive control group, the effect of Shuangdanmingmu capsule on retinal tissue of DR rats was observed under electron microscopy. After HE staining, retinal structure was observed under the light microscope. lmmunohitochemical staining was used to detect the VEGF expression in retina.?RESULTS:Two months after treatment, the layers tissue of retina presented mild edema, capillary pericytes performed edema, mitochondria showed mild swelling and less clear structure, some endothelial cells showed slight proliferation in Shuangdanmingmu group. Compared with the normal group, the expression level of VEGF in retina increased in the other groups, especially in model control group. A significant differential in expression of VEGF was found between Shuangdanmingmu group, positive control group and model control group (P<0. 01).? CONCLUSlON: Shuangdanmingmu capsule can effectively improve the retinal microvascular, reduce edema and necrosis of each layer of retina, improve the ultrastructure of retina's tissue and inhibit VEGF expression in DR rats.

Expression of intestinal tight junction proteins in patients with non-alcoholic fatty liver disease.

BACKGROUND/AIMS: To investigate the expression of tight junction (TJ) proteins including Zonula occludens-1 (ZO-1), occludin and claudin-1 in intestinal epithelial cells in patients with non-alcoholic fatty liver disease (NAFLD) and study its potential association with the pathogenesis of NAFLD. METHODOLOGY: Twenty-eight NAFLD patients with elevated transaminase, 30 NAFLD patients with normal transaminase and 34 healthy volunteers were enrolled. Their biochemical characters were measured and the expression of ZO-1, occludin and claudin-1 proteins in intestinal epithelial cells was assessed by immunohistochemical analysis and its relationship with transaminase levels was also discussed. RESULTS: Significant differences were observed on the levels of BMI, TC, TG, FPG, ALT, and AST among the three groups. The levels in NAFLD patients with elevated transaminase were significantly higher than NAFLD patients with normal transaminase and the latter had higher levels than the volunteers. The expression of ZO-1 and occludin were significantly different among the three groups (chi2 = 14.210, p < 0.01; chi2 = 20.543, p < 0.01). The expression of ZO-1 and occludin decreased gradually from NAFLD with elevated transaminase to healthy volunteers (r = 0.386, p <0.01; r = 0.449, p < 0.01). In NAFLD patients, the levels of the expression of ZO-1 and occludin were negatively correlated with the transaminase level (r = -0.426, p < 0.01; r = -0.597, p < 0.01). The expression of claudin-1 was found among all the three groups but no statistical significance was observed among three groups (chi2 = 0.686, p = 0.953). CONCLUSIONS: The expression of TJ proteins in intestinal epithelial cells are closely related with the occurrence and development of NAFLD. The contribution of different TJ protein varies in maintaining barrier function.

Pharmacokinetics of dauricine in dogs / 中国临床药理学与治疗学

K21. The mean t1/2(?) was (2.7?0.4) h, Vd was about 11.18 L?kg-1.The C-T profile conformed to two compartment open model. The plasma Dau concentration-time curves showed a double-peak phenomenon in all dosages of all dogswhen dauricine was given by intragastric was.The tpeak(1) was (0.8?0.6) ～(1.2?0.5) h,tpeak(2) was (5.2?3.2) ～(6.5?1.9)h,Cmax(2) 0.05) and the AUC was increased in proportion.The drug is eliminated non-linearly when the dosage is above 50 mg?kg-1, the parameters t1/2(el),CL, AUC/X0 shows great difference (P

Pharmacokinetics and relative bioavailability of domestic ibudilast sustained release capsules in healthy volunteers / 中国临床药理学与治疗学

Aim The relative bioavailability of domestic ibudilast sustained release capsules in healthy volunteers was observed.Methods A single oral dose of 20 mg of imported and domestic ibudilast sustained release capsules and 10 mg of ibudilast raw material was separately given to 12 healthy volunteers in a randomized crossover study. Ibudilast concentration in plasma was determined by HPLC method.Results The Cmax were (54.9?9.7),(60.7?9.1) and (62.2?11.5) ?g?L-1; the tmax were (3.8?0.8),(3.9?0.8) and (1.8?0.3) h;the t1/2(ke) were (1.5?1.4),(12.1?1.0) and (3.5?0.5) h,and the AUC(0～t) were (618.1?57.7),(588.1?66.6) and (233.0?46.4) ?g?h?L-1 in imported capsule group, domestic capsule group and raw material group respectively. The relative bioavailability of domestic sustained release capsules of ibudilast is (95.6?11.0)%. Conclusion The results of statistical analysis demonstrate that the imported and domestic sustained capsules have significant character of significantly sustained release and are bioequivalent.