To summarize the current world position on laparoscopic liver surgery.
Multiple series have reported on the safety and efficacy of laparoscopic liver surgery. Small and medium sized procedures have ...become commonplace in many centers, while major laparoscopic liver resections have been performed with efficacy and safety equaling open surgery in highly specialized centers. Although the field has begun to expand rapidly, no consensus meeting has been convened to discuss the evolving field of laparoscopic liver surgery.
On November 7 to 8, 2008, 45 experts in hepatobiliary surgery were invited to participate in a consensus conference convened in Louisville, KY, US. In addition, over 300 attendees were present from 5 continents. The conference was divided into sessions, with 2 moderators assigned to each, so as to stimulate discussion and highlight controversies. The format of the meeting varied from formal presentation of experiential data to expert opinion debates. Written and video records of the presentations were produced. Specific areas of discussion included indications for surgery, patient selection, surgical techniques, complications, patient safety, and surgeon training.
The consensus conference used the terms pure laparoscopy, hand-assisted laparoscopy, and the hybrid technique to define laparoscopic liver procedures. Currently acceptable indications for laparoscopic liver resection are patients with solitary lesions, 5 cm or less, located in liver segments 2 to 6. The laparoscopic approach to left lateral sectionectomy should be considered standard practice. Although all types of liver resection can be performed laparoscopically, major liver resections (eg, right or left hepatectomies) should be reserved for experienced surgeons facile with more advanced laparoscopic hepatic resections. Conversion should be performed for difficult resections requiring extended operating times, and for patient safety, and should be considered prudent surgical practice rather than failure. In emergent situations, efforts should be made to control bleeding before converting to a formal open approach. Utilization of a hand assist or hybrid technique may be faster, safer, and more efficacious. Indications for surgery for benign hepatic lesions should not be widened simply because the surgery can be done laparoscopically. Although data presented on colorectal metastases did not reveal an adverse effect of the laparoscopic approach on oncological outcomes in terms of margins or survival, adequacy of margins and ability to detect occult lesions are concerns. The pure laparoscopic technique of left lateral sectionectomy was used for adult to child donation while the hybrid approach has been the only one reported to date in the case of adult to adult right lobe donation. Laparoscopic liver surgery has not been tested by controlled trials for efficacy or safety. A prospective randomized trial appears to be logistically prohibitive; however, an international registry should be initiated to document the role and safety of laparoscopic liver resection.
Laparoscopic liver surgery is a safe and effective approach to the management of surgical liver disease in the hands of trained surgeons with experience in hepatobiliary and laparoscopic surgery. National and international societies, as well as governing boards, should become involved in the goal of establishing training standards and credentialing, to ensure consistent standards and clinical outcomes.
Whilst catalytic ketone allylation using palladium(0) is well–precedented, nickel(0)‐catalysed equivalents of such reactions remain scarce. We report here the first nickel‐catalysed allylation of ...ketones which uses an easily handled and inexpensive bench‐stable Ni(II) pre‐catalyst. This method avoids generation of stoichiometric by‐products via the use of readily available allyl alcohols, rather than the esters or related derivatives which are often used in such transformations. Under the optimised conditions, 25 monoallylated ketones were obtained in 16% to 98% yield and with high selectivity for the linear (E)–isomers.
Knowledge of vital data such as growth and age at maturity is necessary to develop effective management strategies for endangered species. The Critically Endangered flapper skate (Dipturus ...intermedius) is the largest skate in the North Atlantic and growth information, necessary to assess key life‐history traits, populations’ growth rates and anticipate their response to management measures, is still lacking.
While classical age estimation methods used in fish generally require the analysis of calcified structures, destructive methods are incompatible with conservation objectives for this species. Taking advantage of the high recreational value of the flapper skate, this study uses citizen‐science data originating from photo‐identification of trophy pictures and tag–recapture data supported by anglers to estimate growth in this Critically Endangered species. Using the growth increments measured between recapture events, an individual‐based Von Bertalanffy growth model was fitted to the data using Bayesian inference.
The results confirm that the flapper skate is a long‐lived species with ages estimated as >40 years for the largest individuals captured. Despite this longevity, the model reveals a relatively fast initial growth but relatively late ages at maturity and significant sex‐related differences in both growth rate and maximum size.
These results suggest that population growth rate, and therefore recovery, might be much slower than previously reported. By using citizen science this study provides the necessary information to begin understanding population dynamics and monitor the recovery of an iconic Critically Endangered species.
New lead volatilisation rate and activity data in copper mattes containing low levels of Pb were determined through high-temperature experiments. Measurements on volatilisation rate of lead from ...mattes (Cu-Fe-S) were carried out at temperatures from 1200 to 1570°C by injection of nitrogen into shallow baths. The concentration of lead in the melts covered a range of 200-6 mg.kg
−1
. The rate data exhibited first order behaviour with respect to concentration of Pb. The deduced vapour pressure of Pb in the gas was found to be dependent on the concentration of the Pb in melts and in accord with the equilibrium data on mattes at similar temperatures. Increasing temperature had a strong influence on volatilisation rate and total partial pressure of Pb in the gas phase. Matte grade (45-83 wt%) does not have a strong influence on volatilisation rate, but increasing sulphur potential does have a marked impact in supressing the volatilisation rate.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Vitiligo repigmentation is a complex process in which the melanocyte-depleted interfollicular epidermis is repopulated by melanocyte precursors from hair follicle bulge that proliferate, migrate, and ...differentiate into mature melanocytes on their way to the epidermis. The strongest stimulus for vitiligo repigmentation is narrow-band UVB (NBUVB), but how the hair follicle melanocyte precursors are activated by UV light has not been extensively studied. To better understand this process, we developed an application that combined laser capture microdissection and subsequent whole transcriptome RNA sequencing of hair follicle bulge melanocyte precursors and compared their gene signatures to that of regenerated mature epidermal melanocytes from NBUVB-treated vitiligo skin. Using this strategy, we found up-regulation of TNC, GJB6, and THBS1 in the hair follicle bulge melanocytes and of TYR in the epidermal melanocytes of the NBUVB-treated vitiligo skin. We validated these results by quantitative real-time–PCR using NBUVB-treated vitiligo skin and untreated normal skin. We also identified that GLI1, a candidate stem cell-associated gene, is significantly up-regulated in the melanocytes captured from NBUVB-treated vitiligo bulge compared with untreated vitiligo bulge. These signals are potential key players in the activation of bulge melanocyte precursors during vitiligo repigmentation.
This study aims to investigate the utility of mesenchymal stem cells (MSCs) applied as an epicardial patch during coronary artery bypass graft (CABG) to target hibernating myocardium; that is, tissue ...with persistently decreased myocardial function, in a large animal model.
Hibernating myocardium was induced in juvenile swine (n = 12) using a surgically placed constrictor on the left anterior descending artery, causing stenosis without infarction. After 12 weeks, single-vessel CABG was performed using left internal thoracic artery to left anterior descending artery graft. During CABG, an epicardial patch was applied to the hibernating myocardium region consisting either of MSCs grown onto a polyglactin mesh (n = 6), or sham polyglactin mesh without MSCs (n = 6). Four weeks after CABG and patch placement, cardiac magnetic resonance imaging was performed and cardiac tissue was examined by gross inspection, including coronary dilators for vessel stenosis and patency, electron microscopy, protein assays, and proteomic analysis.
CABG + MSC myocardium showed improvement in contractile function (78.24% ± 19.6%) compared with sham patch (39.17% ± 5.57%) during inotropic stimulation (P < .05). Compared with sham patch control, electron microscopy of CABG + MSC myocardium showed improvement in mitochondrial size, number, and morphology; protein analysis similarly showed increases in expression of the mitochondrial biogenesis marker peroxisome proliferator-activated receptor gamma coactivator 1-alpha (0.0022 ± 0.0009 vs 0.023 ± 0.009) (P < .01) along with key components of the electron transport chain, including succinate dehydrogenase (complex II) (0.06 ± 0.02 vs 0.14 ± 0.03) (P < .05) and adenosine triphosphate synthase (complex V) (2.7 ± 0.4 vs 4.2 ± 0.26) (P < .05).
In hibernating myocardium, placement of a stem cell patch during CABG shows promise in improving myocardial function by improving mitochondrial morphology and function.
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Background. Genetic variations of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV) can affect diagnostic assays and therapeutic interventions. Recent changes ...in prevalence of subtypes/genotypes and drug/immune-escape variants were characterized by comparing recently infected vs more remotely infected blood donors. Methods. Infected donors were identified among approximately 34 million US blood donations, 2006-2009; incident infections were defined as having no or low antiviral antibody titers. Viral genomes were partially sequenced. Results. Of 321 HIV strains (50% incident), 2.5% were non-B HIV subtypes. Protease and reverse transcriptase (RT) inhibitor resistance mutations were found in 2% and 11% of infected donors, respectively.Subtypes in 278 HCV strains (31% incident) yielded la>lb>3a>2b>2a>4a>6d,6e: higher frequencies of 3a in incident cases vs higher frequencies of lb in prevalent cases were found (P = .04). Twenty subgenotypes among 193 HBV strains (26% incident) yielded higher frequencies of A2 in incident cases and higher frequencies of Al, B2, and B4 in prevalent cases (P = .007). No HBV drug resistance mutations were detected. Six percent of incident vs 26% of prevalent HBV contained antibody neutralization escape mutations (P = .01). Conclusions. Viral genetic variant distribution in blood donors was similar to that seen in high-risk US populations. Blood-borne viruses detected through large-scale routine screening of blood donors can complement molecular surveillance studies of highly exposed populations.
Central heating thermostat settings and timing: building demographics Shipworth, Michelle; Firth, Steven K.; Gentry, Michael I. ...
Building research and information : the international journal of research, development and demonstration,
01/2010, Letnik:
38, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Crucial empirical data (currently absent in building energy models) on central heating demand temperatures and durations are presented. These data are derived from the first national survey of energy ...use in English homes and includes monitored temperatures in living rooms, central heating settings reported by participants, along with building, technical, and behavioural data. The results are compared with model assumptions with respect to thermostat settings and heating durations. Contrary to assumptions, the use of controls did not reduce average maximum living room temperatures or the duration of operation. Regulations, policies, and programmes may need to revise their assumptions that adding controls will reduce energy use. Alternative forms of heating control should be developed and tested to ascertain whether their use saves energy in real-world settings. Given the finding that detached houses are heated for longer, these dwellings should be particularly targeted in energy-efficiency retrofit programmes. Furthermore, social marketing programmes could use the wide variation in thermostat settings as the foundation of a 'social norm' programme aimed at reducing temperatures in 'overheated' homes. Finally, building energy models that inform energy policies require firmer foundations in real-world data to improve policy effectiveness. Greater coordination of data collection and management would make more data available for this purpose.
Sont présentées ici des données empiriques critiques (actuellement absentes des modèles énergétiques des bâtiments) concernant les températures demandées et les durées d'utilisation du chauffage central. Ces données proviennent de la première enquête nationale sur l'utilisation de l'énergie dans les foyers anglais et comprennent les températures contrôlées dans les salles de séjour, les réglages du chauffage central indiqués par les participants, ainsi que des données comportementales, techniques et relatives aux immeubles. Les résultats sont comparés aux hypothèses des modèles en ce qui concerne le réglage des thermostats et les durées de chauffage. Contrairement aux hypothèses, l'utilisation de dispositifs de régulation n'a réduit ni les températures maximales moyennes dans les salles de séjour, ni la durée de fonctionnement. Il serait peut-être nécessaire que les réglementations, les politiques et les programmes révisent leurs hypothèses selon lesquelles le fait d'ajouter des dispositifs de régulation réduira l'utilisation d'énergie. D'autres formes de régulation du chauffage devraient être développées et testées afin de vérifier si leur utilisation économise de l'énergie dans des cadres de vie réels. Etant donné la constatation que les maisons individuelles sont chauffées pendant plus longtemps, ces logements devraient être particulièrement ciblés dans les programmes de mise aux normes visant un meilleur rendement énergétique. De plus, les programmes de marketing social pourraient utiliser les grandes variations dans le réglage des thermostats comme base d'un programme de « norme sociale » visant à réduire la température dans les logements « surchauffés ». Enfin, il est nécessaire que les modèles énergétiques des bâtiments, qui ont une influence sur les politiques énergétiques, soient plus fermement basés sur des données réelles afin d'améliorer l'efficacité de ces politiques. Une plus grande coordination dans la collecte et la gestion des données permettrait de disposer de davantage de données à cette fin.
Mots clés: modèle énergétique des bâtiments, chauffage central, systèmes de contrôle, température demandée, commandes du chauffage domestique, demande énergétique, comportement des habitants, réglage des thermostats
Airborne transmission of disease is of concern in many indoor spaces. Here, aerosol dispersion and removal in an unoccupied 4‐bed hospital room were characterized using a transient aerosol tracer ...experiment for 38 experiments covering 4 configurations of air purifiers and 3 configurations of curtains. NaCl particle (mass mean aerodynamic diameter ~3 μm) concentrations were measured around the room following an aerosol release. Particle transport across the room was 1.5–4 min which overlaps with the characteristic times for significant viral deactivation and gravitational settling of larger particles. Concentrations were close to spatially uniform except very near the source. Curtains resulted in a modest increase in delay and decay times, less so when combined with purifiers. The aerosol decay rate was in most cases higher than expected from the clean air delivery rate, but the reduction in steady‐state concentrations resulting from air purifiers was less than suggested by the decay rates. Apparently, a substantial (and configuration‐dependent) fraction of the aerosol is removed immediately, and this effect is not captured by the decay rate. Overall, the combination of curtains and purifiers is likely to reduce disease transmission in multi‐patient hospital rooms.
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