Gap Statistics for Confined Particles with Power-Law Interactions.

We consider the N particle classical Riesz gas confined in a one-dimensional external harmonic potential with power-law interaction of the form 1/r^{k}, where r is the separation between particles. As special limits it contains several systems such as Dyson's log-gas (k→0^{+}), the Calogero-Moser model (k=2), the 1D one-component plasma (k=-1), and the hard-rod gas (k→∞). Despite its growing importance, only large-N field theory and average density profile are known for general k. In this Letter, we study the fluctuations in the system by looking at the statistics of the gap between successive particles. This quantity is analogous to the well-known level-spacing statistics which is ubiquitous in several branches of physics. We show that the variance goes as N^{-b_{k}} and we find the k dependence of b_{k} via direct Monte Carlo simulations. We provide supporting arguments based on microscopic Hessian calculation and a quadratic field theory approach. We compute the gap distribution and study its system size scaling. Except in the range -1-2 with both Gaussian and non-Gaussian scaling forms.

Titanium dioxide fiber saturable absorber for Q-switched fiber laser generation in the 1-micrometer region: publisher's note.

This publisher's note serves to correct an error in Appl. Opt. 58, 3495 (2019)APOPAI0003-693510.1364/AO.58.003495.

High-efficiency picosecond mode-locked laser using a thulium-doped nanoengineered yttrium-alumina-silica fiber as the gain medium.

We report the theoretical and experimental investigation of a self-starting mode-locked fiber laser with a nanoengineered Tm3+-doped yttrium-alumina-silica (YAS) fiber as the gain medium. The YAS fiber exhibits a higher capability of Tm3+ cluster elimination than commercial silica fibers. The Tm3+ fluorescence properties and YAS dispersion are well characterized. As a result, an efficient picosecond mode-locked fiber laser is demonstrated with a slope efficiency of 14.14% and maximum pulse energy of 1.27 nJ. To the best of our knowledge, this is the first mode-locked fiber laser based on a Tm3+-doped YAS fiber. The experimental observation is also supported by the numerical analysis.

The effect of salinity on enterocytozoon hepatopenaei infection in Penaeus vannamei under experimental conditions.

BACKGROUND: Enterocytozoon hepatopenaei (EHP) is an enteric pathogen that affects Penaeus vannamei and Penaeus monodon shrimp in many SE Asian countries. In the western hemisphere, EHP was reported for the first time in 2016 in farmed P. vannamei in Venezuela. Anecdotal evidence suggests that EHP is more prevalent in grow-out ponds where the salinity is high (> 15 parts per thousand (ppt)) compared to grow-out ponds with low salinities (< 5 ppt). Considering that P. vannamei is an euryhaline species, we were interested in knowing if EHP can propagate in P. vannamei in low salinities. RESULTS: In this study, we described an experimental infection using fecal strings as a source inoculum. Specific Pathogen Free (SPF) P. vannamei were maintained at three different salinities (2 ppt, 15 ppt, and 30 ppt) while continuously challenged using feces from known EHP-infected P. vannamei over a period of 3 weeks. The fecal strings, used as a source of EHP inocula in the challenges, was sufficient to elicit an infection in shrimp maintained at the three salinities. The infectivity of EHP in shrimp reared at 2 ppt, 15 ppt, and 30 ppt salinities was confirmed by PCR and histopathology. The prevalence and the severity of the EHP infection was higher at 30 ppt than at 2 ppt and 15 ppt. CONCLUSION: The data suggests that fecal strings are a reliable source of EHP inoculum to conduct experimental challenges via the fecal-oral route. An EHP infection can occur at a salinity as low as 2 ppt, however, the prevalence and the severity of the EHP infection is higher at a salinity of 30 ppt.

Disorderless Quasi-localization of Polar Gases in One-Dimensional Lattices.

One-dimensional polar gases in deep optical lattices present a severely constrained dynamics due to the interplay between dipolar interactions, energy conservation, and finite bandwidth. The appearance of dynamically bound nearest-neighbor dimers enhances the role of the 1/r^{3} dipolar tail, resulting in the absence of external disorder, in quasi-localization via dimer clustering for very low densities and moderate dipole strengths. Furthermore, even weak dipoles allow for the formation of self-bound superfluid lattice droplets with a finite doping of mobile, but confined, holons. Our results, which can be extrapolated to other power-law interactions, are directly relevant for current and future lattice experiments with magnetic atoms and polar molecules.

Harmonically Confined Particles with Long-Range Repulsive Interactions.

We study an interacting system of N classical particles on a line at thermal equilibrium. The particles are confined by a harmonic trap and repel each other via pairwise interaction potential that behaves as a power law ∝∑[under i≠j][over N]|x_{i}-x_{j}|^{-k} (with k>-2) of their mutual distance. This is a generalization of the well-known cases of the one-component plasma (k=-1), Dyson's log gas (k→0^{+}), and the Calogero-Moser model (k=2). Because of the competition between harmonic confinement and pairwise repulsion, the particles spread over a finite region of space for all k>-2. We compute exactly the average density profile for large N for all k>-2 and show that while it is independent of temperature for sufficiently low temperature, it has a rich and nontrivial dependence on k with distinct behavior for -21 and k=1.

Titanium dioxide fiber saturable absorber for Q-switched fiber laser generation in the 1-micrometer region.

A passively Q-switched ytterbium-doped fiber laser (YDFL) operating at 1062 nm was demonstrated by using a segment of 20 cm titanium dioxide-doped fiber saturable absorber (TiO2DF SA). The Q-switched YDFL emerged stably with tunable repetition rates ranging from 32 kHz to 53 kHz as the pump power rose from 109 mW to 233 mW. Within this range of pump power, a maximum output power of 10.1 mW, maximum peak power of 75 mW, and maximum pulse energy of 191 nJ were obtained. The narrowest pulse width of 2.55 µs was attained at the maximum pump power of 233 mW, while the signal-to-noise ratio of the fundamental frequency was 47 dB. This demonstration reveals that the proposed TiO2DF SA is feasible for constructing a flexible and reliably stable Q-switched pulsed fiber laser in the 1-micrometer region.

Global distribution of white spot syndrome virus genotypes determined using a novel genotyping assay.

White spot disease, caused by infection with white spot syndrome virus (WSSV), is a serious panzootic affecting prawn aquaculture. The disease has spread rapidly around the prawn-culturing regions of the world through a number of previously identified mechanisms. The ability to distinguish and trace strains of WSSV is of great benefit to identify, and then limit, the translocation routes of the disease. Here, we describe a novel genotyping method using 34 short tandem repeat regions of the viral genome concurrently. This technique is highly sensitive to strain differences when compared to previous methods. The efficacy of the described method is demonstrated by testing WSSV isolates from around the globe, showing regional genotypic differences. The differences in the genotypes were used to create a global minimum spanning network, and in most cases the observed relationships were substantiated with verification of transboundary movement. This novel panel of STR markers will provide a valuable epidemiological tool for white spot disease. We have applied this to an outbreak of the disease in Queensland, Australia, that occurred in 2016. While the results indicate that the source of this outbreak currently remains cryptic, the analyses have provided valuable insights with which to further study the origins of the strains involved.

The Royal Free Hospital 'hub-and-spoke network model' delivers effective care and increased access to liver transplantation.

OBJECTIVES: 'Hub-and-spoke' networks may be one solution to reduce the geographical inequality in access to liver transplantation (LT) and the growing demands on, and saturation of, LT centres. It is not clear if such networks improve equity of access, deliver comparable patient outcomes or effect patient satisfaction. STUDY DESIGN: Retrospective evaluation of outcomes and patient satisfaction within the Royal Free liver transplant 'hub-and-spoke' network. METHODS: Patient outcomes in those assessed for LT between September 2011 and 2014 at spoke centres (n = 4) were compared retrospectively with those assessed at the LT hub centre. Patient satisfaction questionnaires were completed and changes in LT referral patterns were explored with data obtained directly from NHS Blood and Transplant (NHSBT). RESULTS: A total of 655 patients (180 spoke; 475 hub) were assessed for LT. Patients referred from spoke centres were more likely to have viral hepatitis as an underlying aetiology (72/180 vs 110/475; P < 0.001), or hepatocellular carcinoma (48/180 vs 60/475; P < 0.001) as an indication for LT and were more likely to be listed for LT when compared with hub patients (139/180 vs 312/475, P = 0.005). Mortality on the waiting list (9/123 vs 25/269, P = 0.57), waiting time to LT (64-days vs 78-days, P = 0.91) and Model for End-Stage liver disease (MELD)/United Kingdom End-Stage Liver Disease (UKELD) score (P = 0.24/0.26) in listed patients were equivalent as were 1- and 3-year patient and graft survival rates. Patient satisfaction rates were high at both types of centre, with significantly more patients preferring 'locally delivered care' at spoke vs hub (11/50 vs 70/73, P≤0.0001). Since the development of formal hub-and-spoke networks data from NHSBT based on postcode confirmed a significant increase in patients undergoing LT (153%) from spoke centres, whereas numbers assessed and transplanted from the hub centre have remained static. CONCLUSION: Hub-and-spoke LT networks are effective in offering equivalent clinical outcomes, high patient satisfaction and alleviate clinical pressure on the hub centre. They have to potential to help eliminate the geographical disparity in mortality rates from chronic liver disease.

OSCE as a Summative Assessment Tool for Undergraduate Students of Surgery-Our Experience.

Traditional examination has inherent deficiencies. Objective Structured Clinical Examination (OSCE) is considered as a method of assessment that may overcome many such deficits. OSCE is being increasingly used worldwide in various medical specialities for formative and summative assessment. Although it is being used in various disciplines in our country as well, its use in the stream of general surgery is scarce. We report our experience of assessment of undergraduate students appearing in their pre-professional examination in the subject of general surgery by conducting OSCE. In our experience, OSCE was considered a better assessment tool as compared to the traditional method of examination by both faculty and students and is acceptable to students and faculty alike. Conducting OSCE is feasible for assessment of students of general surgery.

MicroRNAs Involvement in Renal Pathophysiology: A Bird's Eye View.

MicroRNAs (miRNAs) are known to suppress gene expression by binding to messenger RNAs and in turn regulate different pathophysiological processes. Transforming growth factor-ß, mitogen-activated protein kinase signaling, and Wnt signaling-like major pathways associated with miRNAs are involved with kidney diseases. The discovery of miRNAs has provided new insights into kidney pathologies and may provide effective therapeutic strategies. Research has demonstrated the role of miRNAs in a variety of kidney diseases including diabetic nephropathy, lupus nephritis, hypertension, nephritic syndrome, acute kidney injury, renal cell carcinoma, and renal fibrosis. miRNAs are implicated as playing a role in these diseases due to their role in apoptosis, cell proliferation, differentiation, and development. As miRNAs have been detected in a stable condition in different biological fluids, they have the potential to be tools to study the pathogenesis of human diseases with a great potential to be used in disease diagnosis and prognosis. The purpose of this review is to examine the role of miRNA in kidney disease.

Gastrointestinal stromal tumours (GISTs): an insight into clinical practice with review of literature.

BACKGROUND: Gastrointestinal stromal tumours (GISTs) are rare mesenchymal tumours of the gastrointestinal tract. We retrospectively reviewed the clinical management of all patients with GIST presenting to a regional multidisciplinary upper gastrointestinal cancer group in the north of England. METHODS: Clinical, pathological, immunohistochemical treatment strategies, follow-up and outcome data on all patients with GIST between 2007 and 2012 were reviewed. Tumours were categorised by risk according to the National Institutes of Health (NIH) and AFIP models. RESULTS: 36 (85.7%) of 42 tumours were located in the stomach, 5 (11.9%) in the small intestine and 1 (2.4%) in the oesophagus. Median age of patients was 68 (range 43-91) years. 24 patients (57.1%) were female. Tumour size ranged from 1.0  to 12.7 cm with mean size of 5.46 cm. Metastasis was present in 19 (45.2%) patients at diagnosis with distant metastases in 12 patients. Liver was the most common site of metastases. Histology and immunohistochemical analysis was available in 32 (76.2%) patients. Most common histology was spindle cell morphology 17/32 (53.1%) followed by epithelioid 9/32 (28.1%) and mixed morphology 5/32 (15.6%). The positive rate for KIT protein (CD117) was 90.6%, while that for CD34 was 75.0%. 12/25 (48.0%) and 8/23 (34.8%) patients were categorised as high risk as per NIH and AFIP risk scores, respectively. 23/42 (54.8%) patients underwent surgical resection, after which 5/23 (21.7%) had adjuvant imatinib therapy. Imatinib was given as primary therapy in 14/42 (33.3%) patients. CONCLUSIONS: Surgery alone may not be a curative treatment for GISTs. Targeted therapy with imatinib may play an important role in the treatment of GISTs. Further risk categorisation models may be needed to evaluate GIST behaviour and prognosis.

Accelerated Thermal-Aging-Induced Degradation of Organometal Triiodide Perovskite on ZnO Nanostructures and Its Effect on Hybrid Photovoltaic Devices.

Organometal halide perovskite materials are presently some of the pacesetters for light harvesting in hybrid photovoltaic devices because of their excellent inherent electrical and optical properties. However, long-term durability of such perovskite materials remains a major bottleneck for their commercialization especially in countries with hot and humid climatic conditions, thus violating the international standards for photovoltaic technology. Albeit, TiO2 as an electron-transport layer has been well investigated for perovskite solar cells; the high-temperature processing makes it unsuitable for low-cost and large-scale roll-to-roll production of flexible photovoltaic devices. Herein, we have chosen low-temperature (<150 °C)-processable nanostructured ZnO as the electron-selective layer and used a two-step method for sensitizing ZnO nanorods with methylammonium lead iodide (MAPbI3) perovskite, which is viable for flexible photovoltaic devices. We have also elaborately addressed the effect of the annealing duration on the conversion of a precursor solution into the required perovskite phase on ZnO nanostructures. The investigations show that the presence of ZnO nanostructures accelerates the rate of degradation of MAPbI3 films under ambient annealing and thus requires proper optimization. The role of ZnO in enhancing the degradation kinetics of the perovskite layer has been investigated by X-ray photoelectron spectroscopy and a buffer layer passivation technique. The effect of the annealing duration of the MAPbI3 perovskite on the optical, morphological, and compositional behavior has been closely studied and correlated with the photovoltaic efficiency. The study captures the degradation behavior of the commercially interesting MAPbI3 perovskite on a ZnO electron-transport layer and thus can provide insight for developing alternative families of perovskite material with better thermal and environmental stability for application in low-cost flexible photovoltaic technology.

Luminescence and advanced mass spectroscopic characterization of sodium zinc orthophosphate phosphor for low-cost light-emitting diodes.

A new rare-earth-free NaZnPO4:Mn(2+) (NZP:Mn) phosphor powder has been developed by our group and investigated meticulously for the first time using secondary ion mass spectroscopy and chemical imaging techniques. The studies confirmed the effective incorporation of Mn(2+) into the host lattice, resulting in an enhancement of photoluminescence intensity. Phase purity has been verified and structure parameters have been determined successfully by Rietveld refinement studies. The NZP:Mn phosphor powder exhibits strong absorption bands in the ultraviolet and visible (300-470 nm) regions with a significant broad yellow-green (~543 nm) emission due to the characteristic spin forbidden d-d transition ((4)T1→(6)A1) of Mn(2+) ions, indicating weak crystal field strength at the zinc-replaced manganese site. The decay constants are a few milliseconds, which is a pre-requisite for applications in many display devices. The results obtained suggest that this new phosphor powder will find many interesting applications in semiconductor physics, as cost-effective light-emitting diodes (LEDs), as solar cells and in photo-physics.

Review article: depression and the use of antidepressants in patients with chronic liver disease or liver transplantation.

BACKGROUND: The scale of depression in patients with chronic liver disease (CLD) and those who have received orthotopic liver transplantation (OLT) is poorly characterised. Clinicians are uncertain of how best to manage depression within these patients. AIMS: To review the literature evaluating both the prevalence and impact of depression in patients with CLD and post-OLT, and to assess the safety and efficacy of antidepressant use within this context. METHODS: A PubMed search using the phrases 'chronic liver disease', 'cirrhosis', 'liver transplantation', 'depression', 'antidepressant' and the names of specific causes of liver disease and individual antidepressants. RESULTS: Over 30% of cirrhotic patients have depressive features, and they experience worse clinical outcomes than nondepressed cirrhotic patients. CLD patients with chronic hepatitis C are particularly prone to depression, partly related to the use of interferon therapy. OLT patients with depression have higher mortality rates than nondepressed patients; appropriate antidepressant use reverses this effect. Selective serotonin reuptake inhibitors (SSRIs) and selective noradrenaline reuptake inhibitors (SNRIs) are effective and generally safe in both CLD and OLT patients. CONCLUSIONS: Depression is much more prevalent in CLD or OLT patients than is generally recognised, and it adversely affects clinical outcomes. The reasons for this relationship are complex and multifactorial. Antidepressants are effective in both CLD and post-OLT, although lower doses or a reduced dosing frequency may be required to minimise side effects, e.g. exacerbation of hepatic encephalopathy. Further research is needed to establish optimal management of depression in these patients, including the potential role of nonpharmacological treatments.

Assessment of cosmetic outcome of oncoplastic breast conservation surgery in women with early breast cancer: a prospective cohort study.

BACKGROUND: The aim of this study was to assess the cosmetic outcome of patients undergoing oncoplastic breast conserving surgery in Indian population. MATERIALS AND METHODS: A prospective cohort of 35 patients who were eligible for breast conservation surgery was included in the study from year 2007 to 2009. Patients with central quadrant tumors were excluded from the study. A double - blind cosmetic assessment was done by a plastic surgeon and a senior nurse not involved in the management of patients. Moreover, self-assessment was carried out by the patient regarding the satisfaction of surgery, comfort with brasserie, social and sexual life after oncoplastic surgery. RESULTS: In this study, 35 patients underwent oncoplastic breast conservation surgery by various techniques. The cosmetic outcome scores of the surgeon and nurse were analyzed for inter rater agreement using inter-class Correlation Coefficients. There was a good association between them. The risk factors for poor cosmetic outcome was studied by univariate analysis and significant correlation was obtained with age, volume of breast tissue excised and estimated percentage of breast volume excised (P < 0.05). Moreover, 96% of patients were moderately to extremely satisfied with the surgery. Patients were offered an option for cosmetic correction of contralateral breast by mastopexy or reduction mammoplasty however, none of them agreed for another procedure. CONCLUSIONS: Oncoplastic breast surgery helps to resect larger volume of tissue with wider margins around the tumor. It helps to achieve better cosmesis and extends the indications for breast conservation. Most of the patients were satisfied with mere preservation of the breast mound rather than a symmetrical contralateral breast.

Nine scoring models for short-term mortality in alcoholic hepatitis: cross-validation in a biopsy-proven cohort.

BACKGROUND: Several prognostic models have emerged in alcoholic hepatitis (AH), but lack of external validation precludes their universal use. AIM: To validate the Maddrey Discriminant Function (DF); Glasgow Alcoholic Hepatitis Score (GAHS); Mayo End-stage Liver Disease (MELD); Age, Bilirubin, INR, Creatinine (ABIC); MELD-Na, UK End-stage Liver Disease (UKELD), and three scores of corticosteroid response at 1 week: an Early Change in Bilirubin Levels (ECBL), a 25% fall in bilirubin, and the Lille score. METHODS: Seventy-one consecutive patients with biopsy-proven AH, admitted between November 2007-September 2011, were evaluated. The clinical and biochemical parameters were analysed to assess prognostic models with respect to 30- and 90-day mortality. RESULTS: There were no significant differences in the areas under the receiver operating characteristics curve (AUROCs) relative to 30-day/90-day mortality: MELD 0.79/0.84, DF 0.71/0.74, GAHS 0.75/0.78, ABIC 0.71/0.78, MELD-Na 0.68/0.76, UKELD 0.56/0.68. One-week rescoring yielded a trend towards improved predictive accuracies (30-day/90-day AUROCs: 0.69­0.84/0.77­0.86). In patients with admission DF ≥ 32 (n = 31), response to corticosteroids according to ECBL, 25% fall in bilirubin and the Lille model yielded AUROCs of 0.73/0.73, 0.78/0.72 and 0.81/0.82 for a 30-day/90-day outcome respectively. All models showed excellent negative predictive values (NPVs; range: 86­100%), while the positive ones were low (range: 17­50%). CONCLUSIONS: MELD, DF, GAHS, ABIC and scores of corticosteroid response proved to be valid in an independent cohort of biopsy-proven alcoholic hepatitis. MELD modifications incorporating sodium did not confer any prognostic advantage over classical MELD. Based on excellent NPVs, the models are best to identify patients at low risk of death.

Imaging of lung transplant complications.

Since the late 1980s, lung transplantation has emerged as a valid treatment option for some patients with advanced non-neoplastic lung disease. Long-term survival of lung transplant recipients, however, is lower than that of patients with other types of transplantation, because of numerous specific postoperative complications. Thanks to X-ray and CT, radiologists can guide clinicians, helped in this diagnostic approach by the time between the date of injury and date of transplantation. We will detail in this pictorial review the immediate and late surgical complications, the immunological complications, the infectious complications and other late complications.