Endoscopic evaluation during the COVID-19 pandemic: Observational study of the experience in community practices.

Endoscopic screening is used widely to minimize the rates of colorectal cancer cases and deaths. During highly virulent infectious disease pandemics such as the coronavirus disease 2019 (COVID-19) pandemic, it is essential to weigh the risks and benefits of receiving endoscopy, especially in regions with moderately high viral infection rates. An observational study was conducted to assess the number of patients seen for endoscopic procedure at 2 of our surgery centers.

Ultrafast nanometric imaging of energy flow within and between single carbon dots.

Time- and space-resolved excited states at the individual nanoparticle level provide fundamental insights into heterogeneous energy, electron, and heat flow dynamics. Here, we optically excite carbon dots to image electron-phonon dynamics within single dots and nanoscale thermal transport between two dots. We use a scanning tunneling microscope tip as a detector of the optically excited state, via optical blocking of electron tunneling, to record movies of carrier dynamics in the 0.

Unraveling the Fluorescence Mechanism of Carbon Dots with -Single-Particle Resolution.

Unlike quantum dots, photophysical properties of carbon dots (CDs) are not strongly correlated with particle size. The origin of CD photoluminescence has been related to sp domain size and the abundance of oxidized surface defects. However, direct imaging of surface-accessible spatially localized oxidized defects is still lacking.

Excited-State Imaging of Single Particles on the Subnanometer Scale.

At the intersection of spectroscopy and microscopy lie techniques that are capable of providing subnanometer imaging of excited states of individual molecules or nanoparticles. Such approaches are particularly important for imaging macromolecules or nanoparticles large enough to have a high probability of containing a defect. These inevitable defects often control properties and function despite an otherwise ideal structure.

Multi-scale dynamics at the glassy silica surface.

Silica-based glass is a household name, providing insulation for windows to microelectronics. The debate over the types of motions thought to occur in or on SiO glass well below the glass transition temperature continues. Here, we form glassy silica films by oxidizing the Si(100) surface (from 0.

Imaging of Carbon Nanotube Electronic States Polarized by the Field of an Excited Quantum Dot.

Efficient heat dissipation and large gate capacitance have made carbon nanotube field-effect transistors (CNT FETs) devices of interest for over 20 years. The mechanism of CNT FETs involves localization of the electronic structure due to a transverse electric field, yet little is known about the localization effect, nor has the electronic polarization been visualized directly. Here, we co-deposit PbS quantum dots (QDs) with CNTs and optically excite the QD so its excited-state dipolar field biases the local environment of a CNT.

Poor Adherence to Guidelines for Treatment of Chronic Hepatitis B Virus Infection at Primary Care and Referral Practices.

Background & Aims: The American Association for the Study of Liver Diseases (AASLD) guidelines for treatment of chronic hepatitis B virus (HBV) infection have changed with time. We assessed rates of treatment evaluation and initiation in patients with chronic HBV infection from different practice settings in the past 14 years.

Methods: Treatment-naive patients with chronic HBV infection were recruited from different practice settings in California from January 2002 through December 2016.

STM Imaging of Localized Surface Plasmons on Individual Gold Nanoislands.

An optically modulated scanning tunneling microscopy technique developed for measurement of single-molecule optical absorption is used here to image the light absorption by individual Au nanoislands and Au nanostructures. The technique is shown to spatially map, with nanometer resolution, localized surface plasmons (LSPs) excited within the nanoislands. Electrodynamic simulations demonstrate the correspondence of the measured images to plasmonic near-field intensity maps.

Orientation-dependent imaging of electronically excited quantum dots.

We previously demonstrated that we can image electronic excitations of quantum dots by single-molecule absorption scanning tunneling microscopy (SMA-STM). With this technique, a modulated laser beam periodically saturates an electronic transition of a single nanoparticle, and the resulting tunneling current modulation ΔI(x, y) maps out the SMA-STM image. In this paper, we first derive the basic theory to calculate ΔI(x, y) in the one-electron approximation.

Imaging and Manipulating Energy Transfer Among Quantum Dots at Individual Dot Resolution.

Many processes of interest in quantum dots involve charge or energy transfer from one dot to another. Energy transfer in films of quantum dots as well as between linked quantum dots has been demonstrated by luminescence shift, and the ultrafast time-dependence of energy transfer processes has been resolved. Bandgap variation among dots (energy disorder) and dot separation are known to play an important role in how energy diffuses.

Long-term follow-up and suboptimal treatment rates of treatment-eligible chronic hepatitis B patients in diverse practice settings: a gap in linkage to care.

Background And Aims: Despite available effective therapies, only a minority of patients with chronic hepatitis B (CHB) receive treatment. Our goal is to study treatment rates and time to treatment initiation in patients who meet treatment criteria on long-term follow-up.

Methods: We performed a retrospective cohort study of 608 consecutive treatment-eligible patients with CHB (by 2008 US Panel or 2009 American Association for the Study of Liver Disease (AASLD) criteria) at a US community gastroenterology clinic and a university liver clinic between 2007 and 2011.

Tenofovir monotherapy after achieving complete viral suppression on entecavir plus tenofovir combination therapy.

Objectives: It is unclear whether patients with chronic hepatitis B with partial response to entecavir (ETV) who have achieved complete viral suppression (CVS) with ETV plus tenofovir (TDF) combination therapy maintain CVS if switched to TDF or ETV. Our goal was to examine virologic outcomes in such patients.

Methods: This is a retrospective cohort study of 57 ETV partial responders with chronic hepatitis B who showed CVS on ETV+TDF combination therapy, who were switched back to monotherapy with either ETV (n=16) or TDF (n=18), or continued on combination therapy (n=23).

Safety and efficacy of entecavir in adefovir-experienced patients.

Background And Aim: Suboptimal viral suppression with adefovir (ADV) poses a challenge in managing chronic hepatitis B. Few studies have evaluated the efficacy of entecavir (ETV) in ADV-experienced patients. Our aim is to assess treatment effectiveness of ETV in ADV-experienced patients.

Mutations in HBV DNA polymerase associated with nucleos(t)ide resistance are rare in treatment-naive patients.

Background & Aims: Prior studies have detected hepatitis B virus (HBV) DNA polymerase mutations in treatment-naive patients. However, most of these studies used either direct polymerase chain reaction sequencing, which detects these mutations with low levels of sensitivity, or patient cohorts that were not well-characterized. We investigated the prevalence of HBV mutations in DNA polymerase by using a line probe assay.

Similar response to entecavir 0.5 and 1.0 mg in treatment-naïve chronic hepatitis B patients: a case-control study.

Background And Aims: The dose recommendation for entecavir (ETV) is 0.5 mg daily for treatment-naïve chronic hepatitis B (CHB) patients and 1.0 mg daily for lamivudine-refractory patients; however, few data are available for the efficacy of a 1.

Less-established risk factors are common in Asian Americans with hepatitis C virus: a case-controlled study.

Background And Aims: The Centers for Disease Control and Prevention recommend screening for hepatitis C virus (HCV) in patients with injection drug use, blood transfusion before 1992, stigmata of liver disease, or born between 1945 and 1965. The purpose of this study was to examine risk factors for HCV acquisition in Asian Americans.

Methods: This was a case-controlled study, with 471 consecutive patients testing positive for anti-HCV between January 2001 and December 2008.

Low incidence of hepatitis B e antigen seroconversion in patients treated with oral nucleos(t)ides in routine practice.

Background And Aim: Treatment end-point of therapy for patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) includes HBeAg seroconversion, which ranges from 15% to 22% after 1 year of oral nucleos(t)ides according to clinical trials. Our goal was to determine the incidence and predictors of HBeAg seroconversion in such patients in routine clinical practice because they may differ than reported rates.

Methods: We conducted a retrospective cohort study of 333 consecutive treatment-naïve HBeAg-positive patients who were treated for CHB between 1/2000 and 6/2010 at three gastroenterology and liver clinics in the USA.

Low hepatitis B envelope antigen seroconversion rate in chronic hepatitis B patients on long-term entecavir 0.5 mg daily in routine clinical practice.

Aim: Data from registration trials with highly selective patients have shown that hepatitis B envelope antigen (HBeAg)-positive patients with chronic hepatitis B respond well to entecavir (ETV) 0.5 mg daily, with an HBeAg seroconversion rate of 21% at 12 months. However, there are varying data on the treatment outcomes of ETV 0.

Response to higher dose of entecavir 1.0 mg daily in patients with partial response to entecavir 0.5 mg daily.

Background: Despite its high potency against hepatitis B virus (HBV), entecavir (ETV) 0.5 mg daily may not be sufficient to induce complete viral suppression in some patients with very high pretreatment viremia. It is not clear whether ETV 1.

High proportion of hepatitis C virus in community Asian American patients with non-liver-related complaints.

Goals And Background: Besides United States population born between 1945 and 1965, screening for hepatitis C virus (HCV) is not recommended for the general US population. However, HCV may be more prevalent in certain subgroups and screening may be warranted. The goal of this study was to examine the proportion of HCV in a large sample of community Asian American patients presenting for non-liver-related complaints.

Tenofovir monotherapy and tenofovir plus entecavir combination as rescue therapy for entecavir partial responders.

Background And Aims: Despite high potency, a significant proportion of patients treated with entecavir achieve only partial viral suppression. Our goal was to examine the complete viral suppression rate (undetectable HBV DNA PCR levels) with alternative therapies in such patients.

Methods: We retrospectively studied 42 consecutive patients with partial response to entecavir (detectable HBV DNA at ≥12 months of therapy) who were treated at three clinics with rescue therapies: entecavir + adefovir (n = 5), tenofovir (n = 6), and entecavir + tenofovir (n = 31).

High frequency of recurrent viremia after hepatitis B e antigen seroconversion and consolidation therapy.

Background: The primary treatment endpoint for hepatitis B e antigen (HBeAg)-positive chronic hepatitis B is HBeAg seroconversion; however, data on the durability of response are inconsistent.

Goals: Our goal was to investigate the rate of recurrent viremia after HBeAg seroconversion and subsequent discontinuation of therapy.

Methods: We retrospectively studied 88 consecutive Asian American patients who achieved HBeAg seroconversion [loss of HBeAg and development of antibody to HBeAg (anti-HBe)] among 458 HBeAg-positive patients who received oral antiviral therapy at 3 US clinics between March 1998 and November 2010.

Pulmonary surfactant protein A and surfactant lipids upregulate IRAK-M, a negative regulator of TLR-mediated inflammation in human macrophages.

Alveolar macrophages (AMs) are exposed to frequent challenges from inhaled particulates and microbes and function as a first line of defense with a highly regulated immune response because of their unique biology as prototypic alternatively activated macrophages. Lung collectins, particularly surfactant protein A (SP-A), contribute to this activation state by fine-tuning the macrophage inflammatory response. During short-term (10 min-2 h) exposure, SP-A's regulation of human macrophage responses occurs through decreased activity of kinases required for proinflammatory cytokine production.

Undertreatment of Asian chronic hepatitis B patients on the basis of standard guidelines: a community-based study.

Background And Objectives: Previous studies have found that a major proportion of patients with chronic hepatitis B (CHB) do not receive antiviral therapy. The objective of this study was to characterize treatment eligibility on the basis of current guidelines, determine whether eligible patients actually receive treatment, and examine associated predictors.

Methods: We conducted a retrospective study of patients who were evaluated for CHB at two community gastroenterology clinics between April 2007 and February 2009.