Comparative tolerability profiles of the inhaled anaesthetics

Improved understanding of the structure/activity relationship of inhaled anaesthetics has resulted in the synthesis of fluorinated compounds which are more potent and less toxic than their unfluorinated antecedents. The toxic effects of inhaled anaesthetics on the liver and kidney are complex but, in general, are related to the extent to which individual inhaled agents are metabolised. Halothane hepatotoxicity is a rare, idiosyncratic reaction which typically occurs in obese women having more than one exposure to the drug within a short time interval. All currently available volatile anaesthetic drugs have depressant effects on the cardiovascular and respiratory systems; arrhythmias are more likely with halothane than with the fluorinated ethers. Cerebral blood flow tends to increase during inhalation anaesthesia, especially with halothane and in the presence of hypercarbia; isoflurane may be given sparingly during neurosurgical procedures whilst monitoring its end-tidal concentration. Although the volatile agents tend to cause uterine relaxation they may be given safely in low concentration to avoid awareness during Caesarean section. In general, young children require rather higher concentrations of volatile agents than adults and seem to be less susceptible to organ toxicity. Two relatively new volatile agents, sevoflurane and desflurane, offer some advantages over isoflurane but neither is an "ideal drug'. Sevoflurane interacts with soda-lime to produce a series of degradation products, the most important of which is compound A. Production is greatest during low-flow, closed circuit anaesthesia using high inspired concentrations of the drug. Compound A has nephrotoxic potential in rats but the clinical significance of the interaction between sevoflurane and soda-lime is unclear. Nitrous oxide when given for prolonged periods may cause irreversible bone marrow depression.     

Single machine scheduling with controllable processing times to minimize total tardiness and earliness

In most deterministic scheduling problems job processing times are considered as invariable and known in advance. Single machine scheduling problem with controllable processing times with no inserted idle time is presented in this study. Job processing times are controllable to some extent that they can be reduced or increased, up to a certain limit, at a cost proportional to the reduction or increase. In this study, our objective is determining a set of compression/expansion of processing times in addition to a sequence of jobs simultaneously, so that total tardiness and earliness are minimized. A mathematical model is proposed firstly and afterward a net benefit compression–net benefit expansion (NBC–NBE) heuristic is presented so as to acquire a set of amounts of compression and expansion of jobs processing times in a given sequence. Three heuristic techniques in small problems and in medium-to-large instances two meta-heuristic approaches, as effective local search methods, as well as these heuristics are employed to solve test examples. The single machine total tardiness problem (SMTTP) is already NP-hard, so the considered problem is NP-hard obviously. The computational experiments demonstrate that our proposed heuristic is efficient approach for such just-in-time (JIT) problem, especially equipped with competent heuristics.     

Advanced lightwire functionals reduce orthodontic relapse factor

Past orthodontic research by Schwarze in "Expansion and Relapse in Long Follow-Up Studies" concluded "... that orthodontically induced transverse sizes of the dental arches are very unstable." The article further stated that, "the majority of patients showed a decrease of the transverse molar and canine distance from the end of treatment to the follow-up examination." Also emphasized was the fact that "prolonged retention periods do not prevent relapses." These findings are based on orthodontic techniques that focus on movement of teeth and maxillary expansion without regard for existing cranial base and cranial bone distortions.     

Computational studies of the activation of lipases and the effect of a hydrophobic environment

We have investigated the activation pathway of three wild type lipases and three mutants using molecular dynamics techniques combined with a constrained mechanical protocol. The activation of these lipases involves a rigid body hinge-type motion of a single helix, which is displaced during activation to expose the active site and give access to the substrate. Our results suggest that the activation of lipases is enhanced in a hydrophobic environment as is generally observed in experiments. The energy gain upon activation varies between the different lipases and depends strongly on the distribution of the charged residues in the activating loop region. In a low dielectric constant medium (such as a lipid environment), the electrostatic interactions between the residues located in the vicinity of the activating loop (lipid contact zone) are dominant and determine the activation of the lipases. Calculations of the pKas qualitatively indicate that some titratable residues experience significant pK shifts upon activation. These calculations may provide sufficient details for an understanding of the origin and magnitude of a given electrostatic effect and may provide an avenue for exploring the activation pathway of lipases.      

Protective effect of salvianolic acid a on ischemia-reperfusion induced injury in isolated rat heart

BACKGROUND: Recognition of advanced abdominal pregnancy and care of the patient afflicted with it may present formidable challenges. Aside from the difficulty of diagnosing the problem and thereby delaying necessary intervention, management can be difficult at best, even when the condition is relatively uncomplicated. When it is compounded by a life-threatening complication, such as uncontrollable hemorrhage, it challenges the skills of the most experienced obstetrician and the resources of the best-equipped facility and its personnel. CASE: Partial placental separation was encountered at surgery; it progressed intraoperatively despite the care taken to avoid disturbing the placental implantation site. Severe hemorrhage was controlled by a combination of aortic compression, packing and use of large "liver" sutures incorporating the uterine wall for tamponade of the principal placental implantation site, on the mesentery. CONCLUSION: It is important to be prepared to deal with the complication of intense intraabdominal bleeding in the course of intraoperative management of abdominal pregnancy.     

近红外（NIR）光谱在长丝纱和机织物浆料检测中的应用

通过对上浆及已退浆的机织物试样和从织物中分离的经纬和纬纱的测试研究,探索了近红外（ＮＩＲ）光谱鉴定长丝纱与机织物上浆料的可能性与局限性,证实了近红外光谱可用于对纱线与织物上有机物（此时为浆料）的定性分析中,但必须有一个完整的数据库。每一次试验中必须得出清晰明了的试样鉴定结果,以便在数据库中提取具有相近特性的对照试样的数据相对照,最后,必须保证试样在准备和制作时条件一致。     

GnRH agonist treatment decreases progesterone synthesis, luteal peripheral benzodiazepine receptor mRNA, ligand binding and steroidogenic acute regulatory protein expression during pregnancy

Two genes, mutations in which result in the phenotype of tuberous sclerosis (TSC), have recently been cloned. TSC2 on chromosome 16p13.3 encodes the protein tuberin, which appears to have growth regulating properties. TSC1 on chromosome 9q34 encodes hamartin which, as yet, has no specified cellular functions. Polyclonal antibodies were raised to synthetic peptides representing portions of tuberin and hamartin and used in immunoblots and immunohistochemical studies to localize the proteins in surgically resected neocortical tubers from four TSC patients. On Western blots of autopsy brain specimens, K-562 cell, and NT2 lysates, each antibody labelled a single band at the expected molecular weight. In immunohistochemical protocols on paraffin embedded tissue, antibodies to both tuberin and hamartin prominently labelled atypical and dysmorphic neuroglial cells that are a defining feature of TSC tubers. Some abnormal cells within cortical tuber sections were labelled with both tuberin and hamartin antisera. Our results suggest that tuberin and hamartin are both robustly expressed in similar populations of neuroglial cells of TSC tubers, even in the presence of TSC1 or TSC2 germline mutations. The roles of these gene products in normal and abnormal cortical development, tuber pathogenesis and the generation of seizures remain to be defined.