First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment.

We report on the first search for nuclear recoils from dark matter in the form of weakly interacting massive particles (WIMPs) with the XENONnT experiment, which is based on a two-phase time projection chamber with a sensitive liquid xenon mass of 5.9 ton. During the (1.09±0.03) ton yr exposure used for this search, the intrinsic ^{85}Kr and ^{222}Rn concentrations in the liquid target are reduced to unprecedentedly low levels, giving an electronic recoil background rate of (15.8±1.3) events/ton yr keV in the region of interest. A blind analysis of nuclear recoil events with energies between 3.3 and 60.5 keV finds no significant excess. This leads to a minimum upper limit on the spin-independent WIMP-nucleon cross section of 2.58×10^{-47} cm^{2} for a WIMP mass of 28 GeV/c^{2} at 90% confidence level. Limits for spin-dependent interactions are also provided. Both the limit and the sensitivity for the full range of WIMP masses analyzed here improve on previous results obtained with the XENON1T experiment for the same exposure.

Searching for Heavy Dark Matter near the Planck Mass with XENON1T.

Multiple viable theoretical models predict heavy dark matter particles with a mass close to the Planck mass, a range relatively unexplored by current experimental measurements. We use 219.4 days of data collected with the XENON1T experiment to conduct a blind search for signals from multiply interacting massive particles (MIMPs). Their unique track signature allows a targeted analysis with only 0.05 expected background events from muons. Following unblinding, we observe no signal candidate events. This Letter places strong constraints on spin-independent interactions of dark matter particles with a mass between 1×10^{12} and 2×10^{17} GeV/c^{2}. In addition, we present the first exclusion limits on spin-dependent MIMP-neutron and MIMP-proton cross sections for dark matter particles with masses close to the Planck scale.

Final Results of GERDA on the Two-Neutrino Double-ß Decay Half-Life of

We present the measurement of the two-neutrino double-ß decay rate of ^{76}Ge performed with the GERDA Phase II experiment. With a subset of the entire GERDA exposure, 11.8 kg yr, the half-life of the process has been determined: T_{1/2}^{2ν}=(2.022±0.018_{stat}±0.038_{syst})×10^{21} yr. This is the most precise determination of the ^{76}Ge two-neutrino double-ß decay half-life and one of the most precise measurements of a double-ß decay process. The relevant nuclear matrix element can be extracted: M_{eff}^{2ν}=(0.101±0.001).

Erratum: First Search for Bosonic Superweakly Interacting Massive Particles with Masses up to 1 MeV/c

This corrects the article DOI: 10.1103/PhysRevLett.125.011801.

Search for New Physics in Electronic Recoil Data from XENONnT.

We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.

Debris-Filled Duodenal Diverticulum and Lemmel's Syndrome.

We report a case of a 73-year-old woman affected by Lemmel's syndrome, a rare type of obstructive jaundice caused by a periampullary duodenal diverticulum. The patient was admitted to the Emergency Department for pneumonia associated with mild epigastric pain and vomiting. While hospitalized for antibiotic treatment, the appearance of jaundice led us to discover a periampullary duodenal diverticulum by endoscopy and CT scan. The jaundice was successfully managed endoscopically with removal of food debris from the diverticulum.

Destiny for Rendezvous: Is Cholecysto/Choledocholithiasis Better Treated with Dual- or Single-Step Procedures?

Biliary lithiasis is common worldwide, affecting almost 20% of the general population, though few experience symptoms. The frequency of choledocholithiasis in patients with symptomatic cholelithiasis is estimated to be 10-33%, depending on patients' age. Unlike gallbladder lithiasis, the medical and surgical treatment of common bile duct stones is uncertain, having changed over the last few years. The prior gold standard treatment for cholelithiasis and choledocholithiasis was open cholecystectomy with bile duct clearance, choledochotomy, and/or surgical sphincterotomy. In the last 10-15 years, new treatment approaches to the complex pathology of choledocholithiasis have emerged with the advent of endoscopic retrograde cholangiopancreatography (ERCP), laparoscopic surgery, and advanced diagnostic procedures. Although ERCP followed by laparoscopic cholecystectomy is the preferred mode of management, a single-step strategy (laparo-endoscopic rendezvous) has gained acceptance due to lesser morbidity and a lower risk of iatrogenic damage. Given the above, a tailored approach relying on careful evaluation of the disease is necessary in order to minimize complication risks and overall costs. Yet, the debate remains open, with no consensus on the superiority of laparo-endoscopic rendezvous to more conventional approaches.

Duodenal Follicular Lymphoma: Track or Treat?

Duodenal follicular lymphoma (DFL) is a rare variety of non-Hodgkin's lymphoma of the gastrointestinal tract that usually carries a favorable course, recognized as a new entity in 2016. It is usually diagnosed at an early stage located predominantly in the second portion of the duodenum. We report the case of a 74-year-old male patient with epigastric pain in whom gastroscopy revealed white mucosal nodules that were pathologically diagnosed as grade 1-2 DFL. Staging investigations revealed secondary lesions in the spleen and at the base of the tongue together with latero-cervical adenopathy. The tumor was stage IV according to the Lugano staging system. We reviewed the recent (last five years) literature defining the importance of combination therapy in the advanced stage. The patient achieved complete remission of the disease through chemoimmunotherapy following the Rituximab-Bendamustine scheme.

Gas in the Portal Vein: An Emergency or Just Hot Air?

We report the case of a 87-year-old woman admitted to our Emergency Department for mild abdominal pain associated with vomiting. An abdominal X-ray showed gas present in the portal venules of the left hepatic lobe, a finding associated with numerous surgical and medical conditions. The patient was successfully managed with conservative treatment. Isolated intrahepatic gas is a rare radiologic finding; emergency surgery should be performed only when there are signs of associated acute intestinal infarction.

Bleeding Edge Therapy: Ileocolic Intussusception Due to Ileocecal Valve Adenocarcinoma and Its Management in an Adult Patient-Case Report and Literature Review.

Adenocarcinoma as the primary cause of bowel intussusception is uncommon. We describe the case of a 86-year-old patient admitted for ileocecal intussusception due to the presence of adenocarcinoma, located in the ileocecal valve and right colon. The etiologies of intussusception, its diagnosis, and conservative or surgical treatments are discussed, with attention placed on the indications for reduction of the invagination prior to surgical resection.

Popping the Balloon: A Giant Colonic Diverticulum Complicated by Bladder Neck Compression.

Giant colonic diverticulum, defined as a single diverticulum ≤ 4 cm, is rarely encountered. Due to the high incidence of complications related to the disease, obtaining the correct diagnosis early in the disease course is essential. Diagnosis is usually reached by conventional and cross-sectional abdominal radiography. Treatment decisions should be ideally made by a multidisciplinary discussion among surgeons, interventional radiologists, and the patient. The treatment of choice is the surgical management by open or laparoscopic approach.

Final Results of GERDA on the Search for Neutrinoless Double-ß Decay.

The GERmanium Detector Array (GERDA) experiment searched for the lepton-number-violating neutrinoless double-ß (0νßß) decay of ^{76}Ge, whose discovery would have far-reaching implications in cosmology and particle physics. By operating bare germanium diodes, enriched in ^{76}Ge, in an active liquid argon shield, GERDA achieved an unprecedently low background index of 5.2×10^{-4} counts/(keV kg yr) in the signal region and met the design goal to collect an exposure of 100 kg yr in a background-free regime. When combined with the result of Phase I, no signal is observed after 127.2 kg yr of total exposure. A limit on the half-life of 0νßß decay in ^{76}Ge is set at T_{1/2}>1.8×10^{26} yr at 90% C.L., which coincides with the sensitivity assuming no signal.

First Search for Bosonic Superweakly Interacting Massive Particles with Masses up to 1 MeV/c

We present the first search for bosonic superweakly interacting massive particles (super-WIMPs) as keV-scale dark matter candidates performed with the GERDA experiment. GERDA is a neutrinoless double-ß decay experiment which operates high-purity germanium detectors enriched in ^{76}Ge in an ultralow background environment at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. Searches were performed for pseudoscalar and vector particles in the mass region from 60 keV/c^{2} to 1 MeV/c^{2}. No evidence for a dark matter signal was observed, and the most stringent constraints on the couplings of super-WIMPs with masses above 120 keV/c^{2} have been set. As an example, at a mass of 150 keV/c^{2} the most stringent direct limits on the dimensionless couplings of axionlike particles and dark photons to electrons of g_{ae}<3×10^{-12} and α^{'}/α<6.5×10^{-24} at 90% credible interval, respectively, were obtained.

Giant Pelvic Schwannoma: Case Report and Review of the Literature.

INTRODUCTION: Pelvic schwannomas are rare, mostly benign tumors. They are usually asymptomatic until their massive growth compresses adjacent organs. We describe the case of a 53-year-old man with a pelvic schwannoma who initially complained of constipation and urinary retention. AREAS COVERED: We analyzed the clinical presentation, histopathology, diagnostic imaging tools, and the treatment options for pelvic schwannomas, compared with the few other cases reported in the literature. EXPERT COMMENTARY: Pelvic schwannomas are masses that can grow to considerable size, producing symptoms over time. Due to their size and localization, surgery, although difficult, is the only available treatment.

Two's a Charm: Endoscopic Therapy of Multiple Pancreatic Pseudocysts.

Pancreatic pseudocysts commonly complicate acute pancreatitis. They can evolve either asymptomatically or with important symptoms. Treatment can be surgical, endoscopic, or percutaneous. The authors present a case report of a 78-year-old man who developed symptoms of an acute abdomen during hospitalization. A CT scan showed two pancreatic pseudocysts (diameters 10 cm and 7.5 cm) that were successfully drained endoscopically. Multiple pancreatic pseudocysts can be treated successfully via an endoscopic approach.

Dedifferentiated Liposarcoma of the Descending Colon: A Case Report and Review of the Literature.

Dedifferentiated liposarcomas are rare; localization of these tumors in the descending colon is extremely uncommon. We describe the case of a 75-year-old man with a dedifferentiated liposarcoma originating from the descending colon that manifested as partial bowel obstruction. The very uncommon presentation of this rare disease contributed to a challenging diagnostic process. The patient was successfully treated by surgical resection of the mass through left hemicolectomy. Although exceptionally unusual, soft tissue sarcomas should be considered in the differential diagnosis for bowel obstruction. Currently, radical resection of the mass is considered to be the first-line treatment.

Colonic Perforation as Initial Presentation of Amyloid Disease: Case Report and Literature Review.

INTRODUCTION: Amyloidosis is an uncommon disease caused by the deposition of amyloid fibrils in tissues. This disease does not usually require surgical intervention, which could be warranted in the presence of complications such as bleeding, obstruction, or perforation. We present a case of primary amyloidosis of the colon in a patient affected by polymyositis who underwent Hartmann's procedure after a spontaneous colonic perforation. After 2 months of well-being, the patient underwent two consecutive surgical procedures for stenosis of the ostomy orifice. AREAS COVERED: A review of the literature has been performed, gathering case reports highlighting the distribution of this disease by age, gender, location, and treatment when available. EXPERT COMMENTARY: Gastrointestinal amyloid disease is a rare condition, and it could be considered among the rare causes of intestinal perforation. Timely surgical management is often necessary.

Concomitant Heterotopic Pancreas and Endometriosis as a Rare Cause of Ileo-Ileal Intussusception in a Young Woman with Spina Bifida: Case Report and Literature Review.

INTRODUCTION: Isolated heterotopic pancreas (HP) as the primary cause of bowel intussusception is extremely rare. We report a case of a 33-year-old female patient with spina bifida admitted to the Emergency Surgical Department for ileal intussusception due to the presence of heterotopic pancreas associated with endometriosis. AREAS COVERED: Symptomatic ileal intussusception for ectopic pancreas is usually associated with overt gastrointestinal blood loss (predominantly melena), abdominal pain, vomiting, and weight loss. Treatment is universally surgical. EXPERT COMMENTARY: Isolated heterotopic pancreas is a rare condition; it should be considered in the differential diagnosis of bowel intussusception.

Subcapsular Hepatic Hematoma Post-ERCP: Case Report and Review of the Literature.

INTRODUCTION: Hepatic hematoma is a rare but possible complication of ERCP. We describe the case of a 75-year old man with a large, 8 × 12 cm, sub-capsular and intra-parenchymal hematoma post ERCP, affecting the right liver segments and treated conservatively. AREAS COVERED: A review of literature has been performed, highlighting two possible mechanisms: hematoma may occur as the result of accidental laceration of a small intrahepatic vessel by the guidewire, whereas the other hypothesis posits that the hepatic damage is secondary to traction on the biliary system exerted by the balloon. We speculate that in case of anomalies of the biliary tree, the incidence of this complication is higher than expected. EXPERT COMMENTARY: In case of hepatic hematoma post ERCP, a conservative approach should always be considered before proceeding to interventional radiologic procedures or to surgical therapy.

The Great View Forward: The Use of a Colonoscope for Distal Duodenal Stent Placement.

INTRODUCTION: Stent placement in the distal duodenum can be difficult. We describe a case report of a 94-year-old man with metastatic pancreatic head cancer compressing the third and fourth portions of the duodenum, treated by endoscopic stent placement using a colonoscope. AREAS COVERED: A literature review highlighted two possible procedures for stent placement in the distal duodenum, namely forward-viewing and side-viewing endoscopies. Gastroscopes, duodenoscopes, enteroscopes, and colonoscopes have all been suggested for the purpose. For distal lesions, especially when the duodenal wall is stiffened due to compression or infiltration by neoplastic lesions, a conventional upper endoscope can be too short to reach the narrowed site in "push mode," necessitating the use of a longer endoscope. EXPERT COMMENTARY: A colonoscope can be safely and effectively used to accomplish distal duodenal stent placement.