Transport in a long-range Kitaev ladder: role of Majorana and subgap Andreev states

We study local and non-local transport across a two-leg long-range Kitaev ladder connected to two normal metal leads. We focus on the role of the constituent Majorana fermions and the subgap Andreev states. The double degeneracy of Majorana fermions of the individual legs of the ladder gets lifted by a coupling between the two leading to the formation of Andreev bound states. The coupling can be induced by a superconducting phase difference between the two legs of the ladder accompanied by a finite inter-leg hopping. Andreev bound states formed strongly enhance local Andreev reflection. When the ladder and normal metal are weakly coupled, the Andreev bound states, which are the controlling factor, result in weak nonlocal scattering. In sharp contrast, when the ladder - normal metal interface is transparent to electron flow, we find that the subgap Andreev states enhance nonlocal conductance strongly. The features in the local and nonlocal conductances resemble the spectrum of the isolated ladder. Long-range pairing helps lift the degeneracy of the Majorana modes, makes them less localized, and thus inhibits local transport, while aiding non-local transport. In particular, long-range pairing alone (without a superconducting phase difference) can enhance crossed Andreev reflection.Comment: 11 pages, 9 figure

Liposome-A Comprehensive Approach for Researchers

Bangham was first to develop these spherical-shaped nano-vesicles called liposomes in the early 1960s. Today, liposomes have emerged as crucial tools for bettering the delivery of drugs that majorly includes-antifungal drug, peptide hormones, enzymes, vaccines antimicrobial agents, drugs against cancer, and genetic materials. Following the different manufacturing practices and versatile properties liposomes can be categorized in various parameters of size, charge, poly-dispersity index, encapsulation efficiency, solubility properties, and lamellarity. Alteration in such parameters elevates the loading and bioavailability of a drug by giving more clear target specification, desired or controlled release. This bibliographic chapter provides a comprehensive overview of methods for the preparation of liposomes with other perspectives that majorly includes—physio-chemical characteristics, dosage regimen, advantages over other delivery systems, approved liposomal based drugs and other ongoing drugs in clinical trials. It will help researchers to breakthrough more structurally successful delivery vehicles depending upon their various physic-chemical properties

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

Background: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. Methods: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. Findings: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96–1·28). Interpretation: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. Funding: National Institute for Health Research Health Services and Delivery Research Programme

Effectiveness of a national quality improvement programme to improve survival after emergency abdominal surgery (EPOCH): a stepped-wedge cluster-randomised trial

BACKGROUND: Emergency abdominal surgery is associated with poor patient outcomes. We studied the effectiveness of a national quality improvement (QI) programme to implement a care pathway to improve survival for these patients. METHODS: We did a stepped-wedge cluster-randomised trial of patients aged 40 years or older undergoing emergency open major abdominal surgery. Eligible UK National Health Service (NHS) hospitals (those that had an emergency general surgical service, a substantial volume of emergency abdominal surgery cases, and contributed data to the National Emergency Laparotomy Audit) were organised into 15 geographical clusters and commenced the QI programme in a random order, based on a computer-generated random sequence, over an 85-week period with one geographical cluster commencing the intervention every 5 weeks from the second to the 16th time period. Patients were masked to the study group, but it was not possible to mask hospital staff or investigators. The primary outcome measure was mortality within 90 days of surgery. Analyses were done on an intention-to-treat basis. This study is registered with the ISRCTN registry, number ISRCTN80682973. FINDINGS: Treatment took place between March 3, 2014, and Oct 19, 2015. 22 754 patients were assessed for elegibility. Of 15 873 eligible patients from 93 NHS hospitals, primary outcome data were analysed for 8482 patients in the usual care group and 7374 in the QI group. Eight patients in the usual care group and nine patients in the QI group were not included in the analysis because of missing primary outcome data. The primary outcome of 90-day mortality occurred in 1210 (16%) patients in the QI group compared with 1393 (16%) patients in the usual care group (HR 1·11, 0·96-1·28). INTERPRETATION: No survival benefit was observed from this QI programme to implement a care pathway for patients undergoing emergency abdominal surgery. Future QI programmes should ensure that teams have both the time and resources needed to improve patient care. FUNDING: National Institute for Health Research Health Services and Delivery Research Programme

Psychosocial factors in colorectal cancer

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Early results of a rotational flap to treat chronic anal fissures

Background: Treatment of anal fissures has changed dramatically in the past decade. Only a few fail to respond to medical therapy. Sphincterotomy and anal dilatation have fallen out of favour due to the risk of incontinence. Island flaps have been proposed to address this, but 60-70% of flap donor sites break down with complications. We proposed that using a rotational flap would overcome this problem. Methods: Twenty-one patients (14 women,7 men) with chronic anal fissures were treated with rotation flap from perianal skin. The median age was 43 (range 21-76) years. All patients had failed chemical sphincterotomy and showed no signs of improvement following at least a 3-month course of topical GTN 0.2% ointment. Results: The median hospital stay was 2 days. Seventeen patients had complete resolution of symptoms. Only one patient continued to have severe pain. Two developed a recurrent fissure. One patient had a combined fistula-fissure complex at diagnosis and suffered from a breakdown of the flap and donor site. Another patient had had haemorrhoidectomy and an advancement flap in the past. He developed problems with the donor site, which was successfully managed conservatively. One patient had persistent mild pain after surgery, but the cause could not be found. None of the patients suffered continence defects after surgery. Conclusion: Use of a rotational flap is a simple, safe and successful treatment for anal fissures. Donor site problems are minimised using this approach. It should be a treatment of choice when surgery is required for chronic anal fissures, particularly in patients in whom there is a risk of incontinence. © Springer-Verlag 2004

Baseline Quality of Life Factors Predict Long Term Survival after Elective Resection for Colorectal Cancer

Background. Studies have shown an association between baseline quality of life (Qol) and survival in advanced cancers. The aim of this study was to investigate their predictive value in long term survival after elective colorectal cancer resection. Methods. A consecutive series of patients undergoing elective colorectal cancer surgery for nonmetastatic disease were recruited in 2003/04. Patients completed standardized quality of life questionnaires (HADS, FACTC, MRS, and PANAS) prior to and 6 weeks after surgery. Univariate (log-rank test) and multivariate analyses (Cox proportional hazards) were performed to predict long term survival. Results. Ninety-seven patients met the inclusion criteria. Sixty-five (67%) were male and the median age of the group was 70 years. Forty-six (47.5%) patients had died and the mean survival was 1,741 days (median 2159, range 9–2923 days). Preoperative mood rating scale and functional assessment of cancer therapy-colorectal FACT C emotional well-being and postoperative FACT C additional concerns were independent predictors of long term survival. Conclusion. Incorporating psychosocial measures in preoperative assessment of cancer patients could help to identify patients who require assessment with a view to implementing psychosocial interventions. These active interventions to maximize mood and well-being should form an integral part of multidisciplinary treatment in these patients

Sacral neuromodulation for the management of severe constipation: development of a constipation treatment protocol

BackgroundConstipation is a common multifactorial gastrointestinal symptom with quality of life implications. Sacral neuromodulation has been used in the management of severe constipation with mixed results. The aim of this study was to review our experience of sacral neuromodulation as a treatment for chronic constipation and develop a chronic constipation management protocol. MethodsIn patients with severe constipation, failure of conservative management including biofeedback and rectal irrigation were considered for neuromodulation. Temporary stimulation lead was placed in the sacral foramen of eligible patients and pre and post stimulation bowel diaries were compared. Patients with ≥50% improvement in bowel diaries had permanent implant. Patients were followed up at 2 and 4weeks, 3, 6, and 12months, and then yearly with bowel diaries. ResultsTemporary neuromodulation wires were implanted in 21 patients (20 female). Significant bowel diary improvement was seen in 12 (57%) patients (p