Impact of COVID-19 Infection on Pancreato-Biliary Diseases Requiring Endoscopic Retrograde Cholangiopancreatography.

BACKGROUND: Viral infections are known to impact the pancreato-biliary system; however, there are limited data showing that the same is true of COVID-19. Endoscopic retrograde cholangiopancreatography (ERCP) can safely be performed in patients with COVID-19 infection, but outcomes of patients with COVID-19 infections and concomitant pancreatic and biliary disease requiring endoscopic intervention are unknown. AIMS: This study aims to evaluate the severity of pancreaticobiliary diseases and post-ERCP outcomes in COVID-19 patients. METHODS: Patients with pancreato-biliary disease that required inpatient ERCP from five centers in the United States and South America between January 1, 2020, and October 31, 2020 were included. A representative cohort of patients from each month were randomly selected from each site. Disease severity and post-ERCP outcomes were compared between COVID-19 positive and COVID-19 negative patients. RESULTS: A total of 175 patients were included: 95 COVID positive and 80 COVID negative. Mean CTSI score for the patients who had pancreatitis was higher in COVID-positive cohort by 3.2 points (p < .00001). The COVID-positive group had more cases with severe disease (n = 41) versus the COVID-negative group (n = 2) (p < .00001). Mortality was higher in the COVID-19 positive group (19%) compared to COVID-negative group (7.5%) even though the COVID-19-negative group had higher incidence of malignancy (n = 17, 21% vs n = 7, 7.3%) (p = 0.0455). CONCLUSIONS: This study shows that patients with COVID infection have more severe pancreato-biliary disease and worse post-ERCP outcomes, including longer length of stay and higher mortality rate. These are important considerations when planning for endoscopic intervention. CLINICALTRIALS: gov: (NCT05051358).

Ultrafast and Broad-Band Graphene Heterojunction Photodetectors with High Gain.

Graphene possesses an exotic band structure that spans a wide range of important technological wavelength regimes for photodetection, all within a single material. Conventional methods aimed at enhancing detection efficiency often suffer from an extended response time when the light is switched off. The task of achieving ultrafast broad-band photodetection with a high gain remains challenging. Here, we propose a devised architecture that combines graphene with a photosensitizer composed of an alternating strip superstructure of WS2-WSe2. Upon illumination, n+-WS2 and p+-WSe2 strips create alternating electron- and hole-conduction channels in graphene, effectively overcoming the tradeoff between the responsivity and switch time. This configuration allows for achieving a responsivity of 1.7 × 107 mA/W, with an extrinsic response time of 3-4 µs. The inclusion of the superstructure booster enables photodetection across a wide range from the near-ultraviolet to mid-infrared regime and offers a distinctive photogating route for high responsivity and fast temporal response in the pursuit of broad-band detection.

Incidence and risk factors for recurrence of ampullary adenomas after endoscopic papillectomy: Comparative analysis of familial adenomatous polyposis and sporadic ampullary adenomas in an international multicenter cohort.

OBJECTIVES: Endoscopic papillectomy (EP) is a minimally invasive therapy for the management of ampullary adenomas (AA). We conducted this multicenter study to assess the incidence of and factors related to the recurrence of AA after EP in patients with familial adenomatous polyposis (FAP) compared to sporadic AA. METHODS: We included patients who underwent EP for AA at 10 tertiary hospitals. Adenomatous tissue at the resection site at the time of surveillance endoscopies was considered recurrent disease. RESULTS: In all, 257 patients, 100 (38.9%) with FAP and 157 (61%) patients with sporadic AA, were included. Over a median of 31 (range, 11-61) months, recurrence occurred in 48/100 (48%) of patients with FAP and 58/157 (36.9%) with sporadic AA (P = 0.07). Two (2%) FAP patients and 10 (6.3%) patients with sporadic AA underwent surgery for recurrence. On multivariable regression analysis, the recurrence in FAP was higher than in sporadic patients after the first year of follow-up. AA size (hazard ratio [HR] 1.03, 95% confidence interval [CI] 1.001, 1.056), periampullary extension (HR 2.5, 95% CI 1.5, 4.01), and biliary duct dilation (HR 2.04, 95% CI 1.2, 3.4) increased the risk, while en bloc resection (HR 0.6, 95% CI 0.41, 0.9) decreased the risk of recurrence. CONCLUSION: Recurrence rates are high after EP. Most recurrences in sporadic patients occur within the first year of follow-up, but after the first year of follow-up in patients with FAP. Recurrences are higher with larger adenomas, biliary duct dilation, and periampullary extensions, and may be mitigated by en bloc resection. These factors should be considered in decision-making with the patients.

Evaluation of an Individualized Learning Plan Template for the Transition to Residency.

Background Specialty-specific individualized learning plans (ILPs) have been promoted to improve the undergraduate to graduate medical education transition, yet few pilots have been described. Objective To create and report on the feasibility and acceptability of a pilot internal medicine (IM) ILP template. Methods The ILP was created by a group of diverse IM expert stakeholders and contained questions to stimulate self-reflection and collect self-reported readiness data from incoming interns. US IM residency programs were invited to pilot the ILP with interns in spring 2022. Data was used at the programs' discretion. The pilot was evaluated by a post-pilot survey of programs to elicit perceptions of the impact and value of the ILP and analyze anonymous ILP data from 3 institutions. Results Fifty-two IM residency programs agreed to participate with a survey response rate of 87% (45 of 52). Of responding programs, 89% (40 of 45) collected ILPs, thus we report on data from these 40 programs. A total of 995 interns enrolled with 782 completing ILPs (79%). One hundred eleven ILPs were analyzed (14%). Most programs found the ILP valuable to understand incoming interns' competencies (26 of 40, 65%) and areas for improvement (24 of 40, 60%) and thought it should continue (29 of 40, 73%). Programs estimated the ILP took interns 29.2±14.9 minutes and 21.6±10.3 minutes for faculty mentors to complete. The most common barrier was faculty mentor participation. Conclusions An ILP based on interns' self-reported data was feasible and valuable to IM residency programs in understanding interns' competencies and areas for improvement.

Endoscopic Ultrasound-Guided Gallbladder Drainage Versus Percutaneous Drainage in Patients With Acute Cholecystitis Undergoing Elective Cholecystectomy.

INTRODUCTION: Cholecystectomy (CCY) is the gold standard treatment of acute cholecystitis (AC). Nonsurgical management of AC includes percutaneous transhepatic gallbladder drainage (PT-GBD) and endoscopic ultrasound-guided gallbladder drainage (EUS-GBD). This study aims to compare outcomes of patients who undergo CCY after having received EUS-GBD vs PT-GBD. METHODS: A multicenter international study was conducted in patients with AC who underwent EUS-GBD or PT-GBD, followed by an attempted CCY, between January 2018 and October 2021. Demographics, clinical characteristics, procedural details, postprocedure outcomes, and surgical details and outcomes were compared. RESULTS: One hundred thirty-nine patients were included: EUS-GBD in 46 patients (27% male, mean age 74 years) and PT-GBD in 93 patients (50% male, mean age 72 years). Surgical technical success was not significantly different between the 2 groups. In the EUS-GBD group, there was decreased operative time (84.2 vs 165.4 minutes, P < 0.00001), time to symptom resolution (4.2 vs 6.3 days, P = 0.005), and length of stay (5.4 vs 12.3 days, P = 0.001) compared with the PT-GBD group. There was no difference in the rate of conversion from laparoscopic to open CCY: 5 of 46 (11%) in the EUS-GBD arm and 18 of 93 (19%) in the PT-GBD group ( P value 0.2324). DISCUSSION: Patients who received EUS-GBD had a significantly shorter interval between gallbladder drainage and CCY, shorter surgical procedure times, and shorter length of stay for the CCY compared with those who received PT-GBD. EUS-GBD should be considered an acceptable modality for gallbladder drainage and should not preclude patients from eventual CCY.

Gamma-Ray Irradiation Induced Ultrahigh Room-Temperature Ferromagnetism in MoS2 Sputtered Few-Layered Thin Films.

Defect engineering is of great interest to the two-dimensional (2D) materials community. If nonmagnetic transition-metal dichalcogenides can possess room-temperature ferromagnetism (RTFM) induced by defects, then they will be ideal for application as spintronic materials and also for studying the relation between electronic and magnetic properties of quantum-confined structures. Thus, in this work, we aimed to study gamma-ray irradiation effects on MoS2, which is diamagnetic in nature. We found that gamma-ray exposure up to 9 kGy on few-layered (3.5 nm) MoS2 films induces an ultrahigh saturation magnetization of around 610 emu/cm3 at RT, whereas no significant changes were observed in the structure and magnetism of bulk MoS2 (40 nm) films even after gamma-ray irradiation. The RTFM in a few-layered gamma-ray irradiated sample is most likely due to the bound magnetic polaron created by the spin interaction of Mo 4d ions with trapped electrons present at sulfur vacancies. In addition, density functional theory (DFT) calculations suggest that the defect containing one Mo and two S vacancies is the dominant defect inducing the RTFM in MoS2. These DFT results are consistent with Raman, X-ray photoelectron spectroscopy, and ESR spectroscopy results, and they confirm the breakage of Mo and S bonds and the existence of vacancies after gamma-ray irradiation. Overall, this study suggests that the occurrence of magnetism in gamma-ray irradiated MoS2 few-layered films could be attributed to the synergistic effects of magnetic moments arising from the existence of both Mo and S vacancies as well as lattice distortion of the MoS2 structure.

Modified technique of peroral endoscopic myotomy using transnasal ultra-slim gastroscope in a child with achalasia cardia.

Video 1Demonstration of the modified technique of peroral endoscopic myotomy in a small child with achalasia cardia wherein a standard gastroscope could not be used because of anatomical constraints.

Per rectal endoscopic myotomy for Hirschsprung's disease and megacolon.

Hirschsprung's disease (HD) is a congenital disorder characterized by absence of intrinsic ganglion cells of the hindgut. It commonly presents in infancy with refractory constipation and failure to thrive. Short segment HD affecting the rectosigmoid region is the commonest variant. Although surgical or laparoscopic single or multi-stage pull-through procedures have been the gold standard for more than six decades, these procedures are associated with significant morbidity, recurrence, and often multi-stage procedures. Per-rectal endoscopic myotomy (PREM) is a recently described novel minimally invasive procedure based on the principles of third space endoscopy. It is based on the principle to open spastic aganglionic bowel segments by performing a myotomy through a submucosal tunnel. This review describes the patient selection and preparation and technique of PREM and discusses the status of PREM for treatment of HD.

Indications and Outcomes of Per Oral Endoscopic Myotomy from Mouth to Anus.

Third space endoscopy or submucosal endoscopy using a mucosal flap valve allows secure access to the submucosal and deeper layers of the gastrointestinal tract without the risk of a full-thickness perforation. This allows the performance of submucosal tunneling and myotomy for spastic segments of the gastrointestinal tract. Per oral endoscopic myotomy (POEM) has been described for the treatment of achalasia cardia and other spastic esophageal disorders and is widely implemented. Endoscopic pyloromyotomy (G-POEM) has been performed for the treatment of refractory gastroparesis. Z-POEM for Zenker's diverticulum, D-POEM for epiphrenic diverticulum, and per-rectal endoscopic myotomy for treatment of Hirschsprung's disease are described..

Cholangioscopic classification of post-living donor liver transplantation biliary strictures can predict their natural history and response to therapy.

BACKGROUND: The study aimed to assess the morphology of post-living donor liver transplant (LDLT) anastomotic biliary strictures using cholangioscopy and assess the impact of morphology on its prognosis. METHODS: A single centre, prospective, observational study was conducted at a tertiary care teaching hospital from August 2014 to July 2016. Single operator cholangioscopy (SOC) was used to assess post-LDLT anastomotic biliary strictures at presentation in 24 patients. Analysis included demographic and biochemical characteristics, time to stricture development, endoscopic procedural details, time to remodelling and development of recurrence on follow-up. RESULTS: Two distinct patterns of strictures were identified, type I with minimal inflammatory changes and type II with severe inflammatory changes. Guidewire cannulation was successful in 23 out of 24 (95.8%) patients. There was no significant difference between the two types of strictures based on aetiology of liver disease, CTP and MELD scores, time taken for the development or laboratory parameters at presentation. However, type II strictures required more sessions of dilatation (4 vs. 2; P = 0.002), longer duration for resolution (282.5 vs. 201.5 days, P = 0.095) and more number of stents. CONCLUSIONS: Addition of cholangioscopy tends to improve stricture cannulation rates at ERCP. It offers a useful classification of post-LDLT strictures with prognostic and therapeutic significance. Type II strictures tend to require more sessions of endotherapy than type I strictures over a longer duration for remodelling.

Precise Sn-Doping Modulation for Optimizing CdWO4 Nanorod Photoluminescence.

The cadmium tungstate rods have been given much attention due to their potential for usage in numerous luminescent applications. We have prepared single crystalline Sn-doped Cd1-xSnxWO4 (where x = 0, 1, 3, and 5%) nanorods (NRDs) and characterized them using refined X-ray diffraction and TEM analysis, revealing a monoclinic phase and a crystallite size that decreased from 62 to 38 nm as Sn concentration increased. Precise Sn doping modulation in CdWO4 NRDs causes surface recombination of electrons and holes, which causes the PL intensity to decrease as the Sn content rises. The chromaticity diagram shows that an increase in the Sn content caused a change in the emission color from sky blue to light green, which was attributed to the increased defect density. The photoluminescence time decay curve of all samples fit well with double-order exponential decay, and the average decay lifetime was found to be 1.11, 0.93, and 1.16 ns for Cd1-xSnxWO4, x = 0, 1, and 5%, respectively. This work provides an understanding of the behavior of Sn-doped CdWO4 NRDs during electron transitions and the physical nature of emission that could be used in bio-imaging, light sources, displays, and other applications.

Structural and Superconducting Proximity Effect of SnPb Bimetallic Nanoalloys.

We report the superconducting properties between a conventional strong-coupled Pb and weak-coupled Sn superconductor. A series of SnrPb1-r nanoalloys with various compositions r were synthesized, and their superconducting properties were measured using superconducting quantum interference devices (SQUIDs) magnetometer. Our results reveal a superconducting proximity effect (SPE) between immiscible Sn and Pb granules in the range of r = 0.2~0.9, as a weak superconducting coupling can be established with the coexistence of phonon hardening and increased Ginzburg-Landau coherence length. Furthermore, our results provide new insights into improving the study of the superconducting proximity effect introduced by Sn doping.

One-pot hydrothermal preparation and defect-enhanced photocatalytic activity of Bi-doped CdWO4 nanostructures.

In the field of photocatalysis, the suppression of electron-hole recombination through various defects has been an emerging trend to enhance photocatalytic activity. The separation efficiency of electron-hole recombination of well-explored wolframite structured monoclinic CdWO4, prepared using the one-pot hydrothermal method, was further improved by Bi3+ doping in CdWO4. Studies using the partial density of states illustrated that Bi 6s and 6p orbitals altered the electronic band structure to the extent of lowering the band gap, resulting in more photon absorption. The positron annihilation lifetime studies unveiled the formation of cluster defects such as oxygen (V0o, Vo1+, Vo2+) along with cadmium vacancies () in Bi-doped CdWO4. The coexistence and synergy of more adsorption sites of V0o, Vo1+, Vo2+, VCd for dye and O2 molecules, suitable oxide/redox band potentials, the modified electronic band structure especially owing to W-O1-Bi-O2-W linkages, together with high surface area endowed Bi-doped CdWO4 to form ˙O2- radicals played a predominant role in the methyl orange degradation. All the experimental findings demonstrated conclusively that Bi3+ doping at Cd2+ facilitated CdWO4 to exhibit superior photocatalytic activity.

Modified submucosal tunneling endoscopic resection for postcricoid esophageal subepithelial tumor.

Video 1Technique of submucosal tunneling and endoscopic resection for a postcricoid subepithelial esophageal tumor. After surface marking and submucosal elevation, the mucosa was incised. The subepithelial tumor was dissected from the mucosal aspect and enucleated from the muscle layer. En bloc resection was achieved with an intact capsule. The mucosal incision was closed with endoclips.

WSe2/WS2 Heterobilayer Nonvolatile Memory Device with Boosted Charge Retention.

A two-dimensional (2D) nonvolatile memory device architecture to improve the long-term charge retention with the minimum charge loss without compromising storage capacity and the extinction ratio for practical applications has been an imminent demand. To address the current issue, we adopted a novel type-II band-aligned heterobilayer channel comprising vertically stacked monolayer WSe2 nanodots on monolayer WS2. The band offset modulation leads to electron doping from WSe2 nanodots into the WS2 channel without any external driving electric field. As a result, the tested device outperformed with a memory window as high as 34 V and a negligible charge loss of 7% in a retention period of 10 years while maintaining a high extinction ratio of 106. The doping technique presented in this work provides a feasible route to modulate the electrical properties of 2D channel materials without hampering charge transport, paving the way for high-performance 2D memory devices.

Room Temperature Magnetic Memory Effect in Nanodiamond/γ-Fe2O3 Composites.

We report a room temperature magnetic memory effect (RT-MME) from magnetic nanodiamond (MND) (ND)/γ-Fe2O3 nanocomposites. The detailed crystal structural analysis of the diluted MND was performed by synchrotron radiation X-ray diffraction, revealing the composite nature of MND having 99 and 1% weight fraction ND and γ-Fe2O3 phases, respectively. The magnetic measurements carried out using a DC SQUID magnetometer show the non-interacting superparamagnetic nature of γ-Fe2O3 nanoparticles in MND have a wide distribution in the blocking temperature. Using different temperature, field, and time relaxation protocols, the memory phenomenon in the DC magnetization has been observed at room temperature (RT). These findings suggest that the dynamics of MND are governed by a wide distribution of particle relaxation times, which arise from the distribution of γ-Fe2O3 nanoparticle size. The observed RT ferromagnetism coupled with MME in MND will find potential applications in ND-based spintronics.

Phase transformation and room temperature stabilization of various Bi2O3 nano-polymorphs: effect of oxygen-vacancy defects and reduced surface energy due to adsorbed carbon species.

We report the grain growth from the nanoscale to microscale and a transformation sequence from Bi →ß-Bi2O3→γ-Bi2O3→α-Bi2O3 with the increase of annealing temperature. The room temperature (RT) stabilization of ß-Bi2O3 nanoparticles (NPs) was attributed to the effect of reduced surface energy due to adsorbed carbon species, and oxygen vacancy defects may have played a significant role in the RT stabilization of γ-Bi2O3 NPs. An enhanced red emission band was evident from all the samples attributed to oxygen-vacancy defects formed during the growth process in contrast with the observed white emission band from the air annealed Bi ingots. Based on our experimental findings, the air annealing induced oxidation of Bi NPs and transformation mechanism within various Bi2O3 nano-polymorphs are presented. The outcome of this study suggests that oxygen vacancy defects at the nanoscale play a significant role in both structural stabilization and phase transformation within various Bi2O3 nano-polymorphs, which is significant from theoretical consideration.