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151.
The Green’s function of a random walk on a lattice is defined as the inverse of the operatorK-z1, whereK is the matrix of transition rates and z is an arbitrary complex parameter. The Green’s function for a symmetrical random walk in one dimension is here explicitly given in closed form for reflecting, periodic, and absorbing boundaries, and also for an infinite lattice.  相似文献   
152.
Nonthermal pulsed electromagnetic fields, from low frequency to pulse-modulated radio frequency, have been successfully employed as adjunctive therapy for the treatment of delayed and non-union fractures, fresh fractures and chronic wounds. Recent increased understanding of the mechanism of action of electromagnetic fields (EMF) has permitted technologic advances allowing the development of EMF devices which are portable and disposable, can be incorporated into dressings, supports and casts, and can be used over clothing. This broadens the use of non-pharmacological, non-invasive EMF therapy to the treatment of postoperative pain and edema to enhance surgical recovery. EMF therapy is rapidly becoming a standard part of surgical care, and new, more significant, clinical applications for osteoarthritis, brain and cardiac ischemia and traumatic brain injury are in the pipeline. This study reviews recent evidence which suggests that calmodulin (CaM)-dependent nitric oxide signaling is involved in cell and tissue response to weak nonthermal EMF signals. There is abundant evidence that EMF signals can be configured a priori to increase the rate of CaM activation, which, in turn, can modulate the biochemical cascades living cells and tissues employ in response to external insult. Successful applications in pilot clinical trials, coupled with evidence at the cellular and animal levels, provide support that EMF is a first messenger that can modulate the response of challenged biological systems.  相似文献   
153.
Tetrasticta bobbii Zheng & Zhao, sp. n., collected in Nangongshan, Xishuangbanna, Yunnan, is described and illustrated.  相似文献   
154.
155.
Following the premises of the multitarget-directed ligands approach for the drug R&D against neurodegenerative diseases, where Alzheimer’s disease (AD) outstands, we have synthesized and evaluated analogues of the gramine derivative ITH12657 (1-benzyl-5-methyl-3-(piperidin-1-ylmethyl-1H-indole, 2), which had shown important neuroprotective properties, such as blocking effect of voltage-gated Ca2+ channels (VGCC), and prevention of phosphoprotein phosphatase 2A (PP2A) inhibition. The new analogues present different substitutions at the pending phenyl ring, what slightly modified their pharmacological characteristics. The VGCC blockade was enhanced in derivatives possessing nitro groups, while the pro-PP2A feature was ameliorated by the presence of fluorine. Chlorine atoms supplied good activities over the two biological targets aimed; nevertheless that substitution provoked loss of viability at 100-fold higher concentrations (10?μM), what discards them for a deeper pharmacological study. Overall, the para-fluorine derivative of ITH12657 was the most promising candidate for further preclinical assays.  相似文献   
156.
The placental multidrug transporters, P‐glycoprotein (P‐gp, encoded by ABCB1) and breast cancer resistance protein (BCRP, ABCG2) protect the foetus from exposure to maternally derived glucocorticoids, toxins and xenobiotics. During pregnancy, maternal glucocorticoid levels can be elevated by stress or exogenous administration. We hypothesized that glucocorticoids modulate the expression of ABCB1/P‐gp and ABCG2/BCRP in the first trimester human placenta. Our objective was to examine whether dexamethasone (DEX) or cortisol modulate first trimester placental expression of multidrug transporters and determine whether cytotrophoblasts or the syncytiotrophoblast are/is responsible for mediating these effects. Three models were examined: (i) an ex‐vivo model of placental villous explants (7‐10 weeks), (ii) a model of isolated first trimester syncytiotrophoblast and cytotrophoblast cells and (iii) the BeWo immortalized trophoblast cell line model. These cells/tissues were treated with DEX or cortisol for 24 hour to 72 hour. In first trimester placental explants, DEX (48 hour) increased ABCB1 (P < .001) and ABCG2 (P < .05) mRNA levels, whereas cortisol (48 hour) only increased ABCB1 mRNA levels (P < .01). Dexamethasone (P < .05) and cortisol (P < .01) increased BCRP but did not affect P‐gp protein levels. Breast cancer resistance protein expression was primarily confined to syncytiotrophoblasts. BeWo cells, when syncytialized with forskolin, increased expression of BCRP protein, and this was further augmented by DEX (P < .05). Our data suggest that the protective barrier provided by BCRP increases as cytotrophoblasts fuse to form the syncytiotrophoblast. Increase in glucocorticoid levels during the first trimester may reduce embryo/foetal exposure to clinically relevant BCRP substrates, because of an increase in placental BCRP.  相似文献   
157.
Tardive dyskinesia (TD) risk with D2/serotonin receptor antagonists or D2 receptor partial agonists (second‐generation antipsychotics, SGAs) is considered significantly lower than with D2 antagonists (first‐generation antipsychotics, FGAs). As some reports questioned this notion, we meta‐analyzed randomized controlled studies (RCTs) to estimate the risk ratio (RR) and annualized rate ratio (RaR) of TD comparing SGAs vs. FGAs and SGAs vs. SGAs. Additionally, we calculated raw and annualized pooled TD rates for each antipsychotic. Data from 57 head‐to‐head RCTs, including 32 FGA and 86 SGA arms, were meta‐analyzed, yielding 32 FGA‐SGA pairs and 35 SGA‐SGA pairs. The annualized TD incidence across FGA arms was 6.5% (95% CI: 5.3‐7.8%) vs. 2.6% (95% CI: 2.0‐3.1%) across SGA arms. TD risk and annualized rates were lower with SGAs vs. FGAs (RR=0.47, 95% CI: 0.39‐0.57, p<0.0001, k=28; RaR=0.35, 95% CI: 0.28‐0.45, p<0.0001, number‐needed‐to‐treat, NNT=20). Meta‐regression showed no FGA dose effect on FGA‐SGA comparisons (Z=?1.03, p=0.30). FGA‐SGA TD RaRs differed by SGA comparator (Q=21.8, df=7, p=0.003), with a significant advantage of olanzapine and aripiprazole over other non‐clozapine SGAs in exploratory pairwise comparisons. SGA‐SGA comparisons confirmed the olanzapine advantage vs. non‐clozapine SGAs (RaR=0.66, 95% CI: 0.49‐0.88, p=0.006, k=17, NNT=100). This meta‐analysis confirms a clinically meaningfully lower TD risk with SGAs vs. FGAs, which is not driven by high dose FGA comparators, and documents significant differences with respect to this risk between individual SGAs.  相似文献   
158.
Highly conductive and ultrathin 2D nanosheets are of importance for the development of portable electronics and electric vehicles. However, scalable production and rational design for highly electronic and ionic conductive 2D nanosheets still remain a challenge. Herein, an industrially adoptable fluid dynamic exfoliation process is reported to produce large quantities of ionic liquid (IL)‐functionalized metallic phase MoS2 (m‐MoS2) and defect‐free graphene (Gr) sheets. Hybrid 2D–2D layered films are also fabricated by incorporating Gr sheets into compact m‐MoS2 films. The incorporated IL functionalities and Gr sheets prevent aggregation and restacking of the m‐MoS2 sheets, thereby creating efficient and rapid ion and electron pathways in the hybrid films. The hybrid film with a high packing density of 2.02 g cm?3 has an outstanding volumetric capacitance of 1430.5 F cm?3 at 1 A g?1 and an extremely high rate capability of 80% retention at 1000 A g?1. The flexible supercapacitor assembled using a polymer‐gel electrolyte exhibits excellent resilience to harsh electrochemical and mechanical conditions while maintaining an impressive rate performance and long cycle life. Successful achievement of an ultrahigh volumetric energy density (1.14 W h cm?3) using an organic electrolyte with a wide cell voltage of ≈3.5 V is demonstrated.  相似文献   
159.
SnS2 nanoplatelet electrodes can offer an exceptionally high pseudocapacitance in an organic Na+ ion electrolyte system, but their underlying mechanisms are still largely unexplored, hindering the practical applications of pseudocapacitive SnS2 anodes in Na‐ion batteries (SIBs) and Na hybrid capacitors (SHCs). Herein, SnS2 nanoplatelets are grown directly on SnO2/C composites to synthesize SnS2/graphene‐carbon nanotube aerogel (SnS2/GCA) by pressurized sulfidation where the original morphology of carbon framework is preserved. The composite electrode possessing a large surface area delivers a remarkable specific capacity of 600.3 mA h g?1 at 0.2 A g?1 and 304.8 mA h g?1 at an ultrahigh current density of 10 A g?1 in SIBs. SHCs comprising a SnS2/GCA composite anode and an activated carbon cathode present exceptional energy densities of 108.3 and 26.9 W h kg?1 at power densities of 130 and 6053 W kg?1, respectively. The in situ transmission electron microscopy and the density functional theory calculations reveal that the excellent pseudocapacitance originates from the combination of Na adsorption on the surface/Sn edge of SnS2 nanoplatelets and ultrafast Na+ ion intercalation into the SnS2 layers.  相似文献   
160.
Nelore heifers usually begin their reproductive life at ⩾24 months of age mainly due to suboptimal nutritional conditions and genetics. This study aimed to determine the effect of expected progeny difference (EPD) for age at first calving and average daily gain (ADG) on puberty in Nelore (Bos taurus indicus) heifers. A total of 58 weaned heifers (initial BW=174±6 kg; age=9±1 months) were allocated into 28 feedlot pens. Heifers were born from four sires, of which two had low EPD for age at first calving (L; n=33) and two had high EPD for age at first calving (H; n=25). Then, heifers of each EPD were randomly assigned to high ADG (HG; 0.7 kg) or low ADG (LG; 0.3 kg), resulting in four treatments: heifers from L sires were submitted to either HG (LHG; n=17) or LG (LLG; n=16), and heifers from H sires were submitted to either HG (HHG; n=12), or LG (HLG; n=13). The HG heifers were fed a 75% grain diet, whereas the LG heifers received 93% of forage in their diet. Blood samples were collected at 9, 14, 18, 24 and 28 months of age for IGF1 and leptin determination. There was a treatment effect (P<0.01) on the proportion of heifers that attained puberty by 18 (62%, 0%, 0% and 0%), 24 (100%, 6%, 54% and 0%) or 36 (100%, 100%, 100% and 38%) months of age for LHG, LLG, HHG and HLG treatments, respectively. In addition, mean age at puberty was different across treatments (P<0.01). Heifers from the LHG achieved puberty at the earliest age when compared with cohorts from other treatments (18.1, 28.9, 23.9 and 34.5 months for LHG, LLG, HHG and HLG, respectively). Serum IGF1 concentrations were higher for L heifers compared with H cohorts at 9, 14, 18, 24 and 28 months of age (P<0.01; treatment×age interaction), whereas circulating leptin concentrations were higher (P<0.01; age effect) as heifers became older, regardless of the treatments. In conclusion, only Nelore heifers with favorable genetic merit for age at first calving were able to attain puberty by 18 months of age. In heifers with unfavorable genetic merit for age at first calving, supplementary feeding to achieve high ADG was unable to shift the age at puberty below 24 months.  相似文献   
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