655 research outputs found
Toxicity Testing of Restorative Dental Materials Using Brine Shrimp Larvae (Artemia salina)
This study investigated the effect of extracts of different composites, glass ionomer cement (GIC)s and compomers on the viability of brine shrimp larvae. Ethanolic extracts of four dental composites (Z-100; Solitaire 2; Filtek P60 and Synergy), a conventional GIC (Ketac-Fil), a resin-modified glass ionomer cement (Vitremer), two compomers (F2000; Dyract AP), and a flowable compomer (Dyract Flow) were prepared from each material. Following evaporation of the ethanol, the extracts were resuspended in distilled water, which was then used to test the effects on the viability of brine shrimp larvae. For the composites, the extract of Synergy was the least toxic (88% viability) followed by the extracts of Solitaire 2, Z100 and P60 (75%, 67.5% and 50% viability, respectively). One-way ANOVA revealed highly significant differences between the resin composite materials (
Joint Energy and Reserve Scheduling of a Wind Power Producer in a Peer-to-Peer Mechanism
This paper proposes a risk constrained decision making problem for wind power producers (WPPs) in a competitive environment. In this problem, the WPP copts to maximize its likely profit whereas aggregators want to minimize their payments. So, this bi-level problem is converted to a single level one. Then, the WPP offers proper prices to the aggregators to attract them to supply their demand. Also, these aggregators can procure reserve for the WPP to compensate its uncertainties. Therefore, through a peer-to- peer (P2P) trading mechanism, the WPP requests the aggregators to allocate reserve to cover the uncertainties of the wind generation. Also, due to the presence of uncertain resources of the problem, a risk measurement tool is applied to the problem to control the uncertainties. The effectiveness of the model is assessed on realistic data from the Nordpool market and the results show that as the loads become responsive, more loads are allowed to choose their WPP to supply their load. Also, the reserve that is provided by these responsive loads to the WPP increases.©2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.fi=vertaisarvioitu|en=peerReviewed
Risk-Averse Optimal Energy and Reserve Scheduling for Virtual Power Plants Incorporating Demand Response Programs
This paper addresses the optimal bidding strategy problem of a virtual power plant (VPP) participating in the dayahead (DA), real-time (RT) and spinning reserve (SR) markets (SRMs). The VPP comprises a number of dispatchable energy resources (DERs), renewable energy resources (RESs), energy storage systems (ESSs) and a number of customers with flexible demand. A two-stage risk-constrained stochastic problem is formulated for the VPP scheduling, where the uncertainty lies in the energy and reserve prices, RESs production, load consumption, as well as calls for reserve services. Based on this model, the VPP bidding/offering strategy in the DA market (DAM), RT market (RTM) and SRM is decided aiming to maximize the VPP profit considering both supply and demandsides (DS) capability for providing reserve services. On the other hand, customers participate in demand response (DR) programs by using load curtailment (LC) and load shifting (LS) options as well as by providing reserve service to minimize their consumption costs. The proposed model is implemented on a test VPP and the optimal decisions are investigated in detail through a numerical study. Numerical simulations demonstrate the effectiveness of the proposed scheduling strategy and its operational advantages and the computational effectiveness.© Institute of Electrical and Electronics Engineers.fi=vertaisarvioitu|en=peerReviewed
The Study of Newborns with Congenital Gastrointestinal Tract Obstruction
Introduction: Gastrointestinal Tract Obstruction
(GITO) is one of the most common causes of surgical
emergencies in newborns. Management of these
patients depends on the site of obstruction, associated
anomalies, the time of diagnosis and the surgery. Aim:
The purpose of this study was to evaluate clinical
manifestations, associated anomalies and the outcome
of these patients with GITO admitted to Imam Reza
and Razi Hospitals of Kermanshah. Material and
Methods: This is an observational study, which is
conducted to investigate all the newborns, admitted to
the Neonatal Intensive Care Unit (NICU) of Imam
Reza & Razi Hospital of Kermanshah during ten years
from 2002 to 2012 with diagnosis of GITO. The
history of the newborn, operation records and case
records of the patients in addition to clinical and paraclinical
conditions and their pathological results were
studied. Results: During the study period, 235 cases of
GITO were investigated. Among them, 63 were admitted
with imperforate anus, 62 with Hirschsprung's
disease, 52 with esophageal atresia, 9 with ileal atresia,
17 with jejunal atresia, and 16 with duodenal obstruction
and 6 with colonic atresia. The most common
symptoms at the time of admission were abdominal
distension in 108, absence of meconial defecation in
85, and bile vomiting in 42 cases. 189 (80.4%) of
newborns were operated. The overall mortality rate of
newborns under study was 31.2%. The highest rate of
mortality was observed in newborns with esophageal
atresia 61.5%. Conclusion: The results of the present
study showed that approximately 5% of the cases
admitted to NICU suffered from congenital GITO.
Considering the high number of cases and the
increased probability of death in these patients, close
attention, better management and treatment of these
patients seems crucial
Patient focused registries can improve health, care, and science.
Eugene Nelson and colleagues call for registries of care data to be transformed into patient centred interactive learning systemsThis work is supported by funding from the Robert Wood Johnson Foundation (Grants: #71211 and 72313), the Cystic Fibrosis Foundation (Grant #OCONNO04Q10), and the Crohn’s and Colitis Foundation of America Quality of Care Initiative (Grant #3372). TSM was funded by the Multidisciplinary Clinical Research Center for Musculoskeletal Diseases at Dartmouth (P60 AR-062799, A. Tosteson, PI), sponsored by the National Institute for Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health. EE was funded by The Swedish Research Council for Health, Work Life and Welfare (#2014-4238). MDW is supported by a Wellcome Trust Senior Investigator award (WT09789).This is the final version of the article. It first appeared from BMJ Group via https://doi.org/10.1136/bmj.i331
Кінетика тетанусу musculus gastrocnemius в алкоголізованих щурів з експериментально-індукованою васкулярною ішемією задніх кінцівок за умов низькочастотної м’язової втоми
Alcohol intoxication and ischemic injury of skeletal muscles often accompany each other. It is shown that patients hospitalized with chronic alcoholism develop muscle fatigue. Skeletal muscle dysfunction in alcohol-dependent patients is caused by ethanol-associated myofibrillar atrophy and metabolic disbalance, while compression-ischemic lesions result from unconsciousness of the patient, in case of taking the critical alcohol dose. Therefore, the aim of this study is to discover typical m. gastrocnemius (cap. med.) tetanic kinetics changes in alcohol intoxicated rats with experimentally induced vascular ischemia of hindlimb muscles under conditions of low-frequency progressive muscle fatigue. Experiments were carried out on 10 young male Wistar rats (149.5 ± 5.8 g) kept under standard vivarium conditions and diet. The investigation was conducted in two phases: chronic (30 days) and acute (3 hours) experiment. All surgical procedures were carried out aseptically under general anesthesia. Ishemic m. gastrocnemius (cap. med.) tetanic kinetic changes and force productivity in alcohol intoxicated rats were investigated in the isometric mode, with direct electrical stimulation. The fatigue of m. gastrocnemius (cap. med.) was evaluated by three characteristic criteria: the first sag effect, the secondary force rise, the second sag effect. There have been 10 similar experiments: 5 series in each study group with 10 tetanic runs in each series. The highest amplitude of the native m. gastrocnemius (cap. med.) tetanus relative to isoline was taken as 100% force response. The same pattern of m. gastrocnemius (cap. med.) low-frequency fatigue development was found in both rat groups under study. It is evidenced by the absence of substantial m. gastrocnemius (cap. med.) tetanus kinetics differences in alcohol intoxicated rats, compared with non-alcohol intoxicated rats during fatigue test. However, the appreciable m. gastrocnemius (cap. med.) tetanic force reduction in alcohol intoxicated rats, compared with non-alcohol intoxicated rats is found. During fatigue test, m. gastrocnemius (cap. med.) of non-alcohol intoxicated rats featured 75.0 ± 17.4% loss, that of alcohol intoxicated rats has lost 75.0 ± 17.0%, while the native one – 62.0 ± 11.3% of initial force. Contraction-relaxation cycle kinetics changes were not identified. Thus, the tetanus kinetics and tetanic force change of m. gastrocnemius (cap. med.) in alcohol intoxicated rats indicates no changes in the process of development of low-frequency muscle fatigue, compared with non-alcohol intoxicated rats. Low force productivity of m. gastrocnemius (cap. med.) in alcohol intoxicated rats compared with non-alcohol intoxicated ones directly results from alcoholic myopathy complicated by vascular ischemia.Досліджено зміну кінетики тетанусу m. gastrocnеmius (cap. med.) в алкоголізованих щурів з експериментально-індукованою унілатеральною васкулярною ішемією м’язів задніх кінцівок за умов прогресивної низькочастотної м’язової втоми. Кінетика тетанусу m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими не зазнає суттєвих змін. Характерною ознакою низькочастотної втоми m. gastrocnеmius (cap. med.) за умов ішемії є швидка поява вторинного провисання механограми тетанусу протягом експерименту, що не дозволяє м’язу досягти оптимального рівня тетанічної сили. Встановлено значне зменшення силової продуктивності m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими за умов низькочастотної м’язової втоми. Оцінка змін силової продуктивності m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими вказує на синергічну взаємодію хронічної алкогольної інтоксикації та васкулярної ішемії в обмеженні моторної функції. Обговорено синергічний зв’язок алкоголь-асоційованої м’язової атрофії та ішемічного ушкодження м’яких тканин нижніх кінцівок у патогенезі моторної дисфункції. Досліджено зміну кінетики тетанусу m. gastrocnеmius (cap. med.) в алкоголізованих щурів з експериментально-індукованою унілатеральною васкулярною ішемією м’язів задніх кінцівок за умов прогресивної низькочастотної м’язової втоми. Кінетика тетанусу m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими не зазнає суттєвих змін. Характерною ознакою низькочастотної втоми m. gastrocnеmius (cap. med.) за умов ішемії є швидка поява вторинного провисання механограми тетанусу протягом експерименту, що не дозволяє м’язу досягти оптимального рівня тетанічної сили. Встановлено значне зменшення силової продуктивності m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими за умов низькочастотної м’язової втоми. Оцінка змін силової продуктивності m. gastrocnеmius (cap. med.) в алкоголізованих щурів порівняно з неалкоголізованими вказує на синергічну взаємодію хронічної алкогольної інтоксикації та васкулярної ішемії в обмеженні моторної функції. Обговорено синергічний зв’язок алкоголь-асоційованої м’язової атрофії та ішемічного ушкодження м’яких тканин нижніх кінцівок у патогенезі моторної дисфункції.
The efficacy and safety of ketamine for depression in patients with cancer: A systematic review
Management of depression in the oncology population includes supportive psychotherapeutic interventions with or without psychotropic medication, which take time to demonstrate effectiveness. Fast-acting interventions, like ketamine, can provide a rapid antidepressant effect; however, there has been limited research on effects of ketamine among cancer patients. The objective of this review is to provide an overview of research on the efficacy and safety of ketamine on depression in patients with cancer. We reviewed the published literature in MEDLINE® (via PubMed®), EMBASE, and Scopus from 1 January 1982 to 20 October 2022. We screened the retrieved abstracts against inclusion criteria and conducted a full-text review of eligible studies. Following extraction of data from included studies, we used a framework analysis approach to summarize the evidence on using ketamine in patients with cancer. All 5 included studies were randomized clinical trials conducted in inpatient settings in China. In all included studies ketamine was administered intravenously. Three studies used only racemic ketamine, and two studies used both S-ketamine and racemic ketamine. All included studies reported ketamine a tolerable and effective drug to control depression symptoms. Included studies showed administration of sub-anesthesia ketamine significantly improves postoperative depression among patients with cancer. [Abstract copyright: © 2023 The Author(s).
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Fully kinetic simulations of magnetic reconnction in semi-collisional plasmas
The influence of Coulomb collisions on the dynamics of magnetic reconnection is examined using fully kinetic simulations with a Monte-Carlo treatment of the Fokker-Planck collision operator. This powerful first-principles approach offers a bridge between kinetic and fluid regimes, which may prove useful for understanding the applicability of various fluid models. In order to lay the necessary groundwork, the collision algorithm is first carefully bench marked for a homogeneous plasma against theoretical predictions for beam-plasma interactions and electrical resistivity. Next, the collisional decay of a current layer is examined as a function of guide field, allowing direct comparisons with transport theory for the parallel and perpendicular resistivity as well as the thermoelectric force. Finally, the transition between collisional and collision less reconnection is examined in neutral sheet geometry. For modest Lundquist numbers S {approx}< 1000, a distinct transition is observed when the thickness of the Sweet-Parker layers falls below the ion inertia length {delta}{sub sp} {approx}< d,. At higher Lundquist number, deviations from the Sweet-Parker scaling are observed due to the growth of plasmoids (secondary-islands) within the elongated resistive layer. In certain cases, this instability leads to the onset of fast reconnection sooner than expected from {delta}{sub sp} {approx} d, condition. After the transition to fast reconnection, elongated electron current layers are formed which are unstable to the formation of new plasmoids. The structure and time-dependence of the electron diffusion region in these semi-collisional regimes is profoundly different than reported in two-fluid simulations
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