cssi/SciSciGPT-SciSciNet huggingface dataset:
Dynamics of filaments and membranes in a viscous fluid

Motivated by the motion of biopolymers and membranes in solution, this article presents a formulation of the equations of motion for curves and surfaces in a viscous fluid. The focus is on geometrical aspects and simple variational methods for calculating internal stresses and forces, and the full nonlinear equations of motion are derived. In the case of membranes, particular attention is paid to the formulation of the equations of hydrodynamics on a curved, deforming surface. The formalism is illustrated by two simple case studies: (1) the twirling instability of straight elastic rod rotating in a viscous fluid and (2) the pearling and buckling instabilities of a tubular liposome or polymersome.
Determination of the persistence of pharmaceuticals in biosolids using liquid-chromatography tandem mass spectrometry.

Sludge generated in waste water treatment process can be a major sink for some pharmaceutical and personal care products (PPCPs). The land application of sewage sludge (in the form of biosolids in the United States) can therefore potentially introduce PPCPs into the environment. After treatment, biosolids are often subjected to a storage period before land application. However, little information is available with regard to the fate of PPCPs in biosolids during the storage. In this work, the persistence of seven pharmaceuticals and one antibacterial was evaluated using ultrasonic extraction and liquid-chromatography tandem mass spectrometry (LC–MS/MS). The impacts of aeration and sunlight exposure were investigated. During the experiment, no elimination was observed for carbamazepine, triclosan, and ciprofloxacin while elimination was found for tetracycline, doxycycline, clindamycin, erythromycin, and clarithromycin. Using an availability-adjusted kinetic model, the 50% dissipation time was 37 to >77 d for tetracycline, 53 to >77 d for doxycycline, 1.0–1.6 d for clindamycin, 1.1–1.9 d for clarithromycin, and 7.0–17 d for erythromycin. Those compounds were found more persistent under anaerobic conditions than aerobic condition with a longer 50% dissipation time by a factor of 1.5–2. However, minor impact was observed from sunlight irradiation. Published by Elsevier Ltd.
Mating Success of Male Mediterranean Fruit Flies Following Exposure to Two Sources of α-Copaene, Manuka Oil and Mango

Abstract Recent studies on the Mediterranean fruit fly (medfly), Ceratitis capitata (Wied.), have demonstrated an increase in male mating competitiveness following exposure to particular plant structures or products, including the fruit and fruit-derived oil of orange trees, the bark and fruits of guava trees, and ginger root oil. Although it is not known which compound(s) was responsible for the enhanced mating success, all the performance-boosting substances tested thus far contain the sesquiterpene hydrocarbon a-copaene, and α-copaene tested alone was found to increase mating success in male medflies. As the concentration of α-copaene and other terpenes vary among plant species, it is not known whether exposure to α-copaene-bearing plants (or their derived oils) will universally influence the mating behavior of male medflies. The goal of this study was to describe the results of mating trials conducted after male exposure to 2 previously untested sources of α-copaene, manuka oil (from the New Zealand m...
Particle Films for Suppression of the Codling Moth (Lepidoptera: Tortricidae) in Apple and Pear Orchards

Studies were conducted in 1997and 1998 to evaluate the effects of three particle film formulations consisting of kaolin and adjuvants on neonate larvae, ovipositing adult females, and eggs of the codling moth, Cydia pomonella (L.). Neonate larval walking speed, fruit discovery rate, and fruit penetration rate on apple host plants coated with particle films were significantly lower than on host plants without particle films in laboratory assays. Females oviposited less on host plants covered with a particle film residue than on untreated plants in laboratory choice and no-choice tests. Hatch rate of codling moth neonate larvae was unaffected by particle films sprayed on host plants either before or after oviposition. Fruit infestation rates were significantly reduced on particle film-treated trees compared with untreated trees for both first- and second-generation codling moth in field trials in both apple and pear orchards. Particle films appear to be a promising supplemental control approach for codling moth in orchards where moth density is high, and may represent a stand-alone method where moth densities are lower.
Health Systems Are Capable of Handling a REMS.

To the Editor: I would like to comment on the article in the February 2014 issue of P&T entitled “Specialty Pharmacy Networks for Hospitals in the Offing” by Stephen Barlas (pages 123–125, 143). I would like to commend the author on an excellent article that summarizes all the issues related to specialty pharmacy and health systems. The heart of the issue with specialty pharmacy is limited distribution. There is a myth that REMS requires limited distribution. Mr. Barlas stated that “The FDA forces some manufacturers to limited distribution to specialty pharmacies as the price of their approval.” I believe that may be the opinion of many in the pharmaceutical industry; however it is not supported by fact. Indeed, the FDA’s most stringent REMS programs do not require limited distribution, specifically those for transmucosal immediate release fentanyl, thalidomide, clozapine, and isotretinoin. Mr. Barlas went on to describe the difficulty health systems have in implementing REMS programs; he stated “those and other tough conditions can be hard for a hospital pharmacy to meet.” I would like to point out that health systems across the country are trusted with clinical trials prior to drug approval, and certainly are more than capable of handling a REMS program post-approval. It is unbelievable and embarrassing when a drug that was available to the health system during clinical trials would not be available post-approval due to “limited distribution systems.” We providers in major academic health systems are capable of implementing REMS. I would also like to point out that some new specialty drugs without REMS have limited distribution requirements. It is unclear why the distribution of non-REMS drugs is limited to specialty pharmacies, since there are no safety, handling, or administration requirements necessary for these drugs. Specifically, dimethyl fumarate and dalfampridine are oral agents for multiple sclerosis that do not have REMS requirements; however, the distribution is restricted to specialty pharmacies. There is no apparent reason why health systems, with their direct contact with the patients and access to the electronic medical records, would not be able to dispense the drugs directly to outpatients. These access restrictions may pose problems in start of therapy and transitions in care that affect patient outcomes. I look forward to a continuing dialogue on specialty pharmacy and restricted distribution in P&T.
Investigation on HIV,TP and HCV infection situation and related behaviors among employees of food industry and public places in Changping district

Objective:To know the infection situation of HIV,TP and HCV and associated behaviors in employees engaged in food industry and public places in Changping district.Methods: In June of 2011,questionnaire investigation and serological test of HIV,TP and HCV were carried out among employees by continuous sampling from food industry and public places.Results: A total of 1430 employees were involved in this investigation,there was 1 HIV positive case(0.14%),1 TP positive case(0.07%),2 HCV positive cases(0.14%).The infection rates of HIV,TP and HCV were the highest in population under 40 years old,due to low awareness rate of HIV spread route and low usage rate of condom.Conclusion: Employees in food industry and public places were the high-risk population of HIV,TP and HCV.Therefore,in addition to routine serological examination,the serological monitoring on HIV,TP and HCV should be taken as the necessary measure to timely discover the source of infection,effectively prevent and control the occurrence and prevalence of HIV,TP and HCV.
Astrocyte arachidonate and palmitate uptake and metabolism is differentially modulated by dibutyryl-cAMP treatment

Astrocytes play a vital role in brain lipid metabolism; however the impact of the phenotypic shift in astrocytes to a reactive state on arachidonic acid metabolism is unknown. Therefore, we determined the impact of dibutyryl-cAMP (dBcAMP) treatment on radiolabeled arachidonic acid ([1-(14)C]20:4n-6) and palmitic acid ([1-(14)C]16:0) uptake and metabolism in primary cultured murine cortical astrocytes. In dBcAMP treated astrocytes, total [1-(14)C]20:4n-6 uptake was increased 1.9-fold compared to control, while total [1-(14)C]16:0 uptake was unaffected. Gene expression of long-chain acyl-CoA synthetases (Acsl), acyl-CoA hydrolase (Acot7), fatty acid binding protein(s) (Fabp) and alpha-synuclein (Snca) were determined using qRT-PCR. dBcAMP treatment increased expression of Acsl3 (4.8-fold) and Acsl4 (1.3-fold), which preferentially use [1-(14)C]20:4n-6 and are highly expressed in astrocytes, consistent with the increase in [1-(14)C]20:4n-6 uptake. However, expression of Fabp5 and Fabp7 were significantly reduced by 25% and 45%, respectively. Acot7 (20%) was also reduced, suggesting dBcAMP treatment favors acyl-CoA formation. dBcAMP treatment enhanced [1-(14)C]20:4n-6 (2.2-fold) and [1-(14)C]16:0 (1.6-fold) esterification into total phospholipids, but the greater esterification of [1-(14)C]20:4n-6 is consistent with the observed uptake through increased Acsl, but not Fabp expression. Although total [1-(14)C]16:0 uptake was not affected, there was a dramatic decrease in [1-(14)C]16:0 in the free fatty acid pool as esterification into the phospholipid pool was increased, which is consistent with the increase in Acsl3 and Acsl4 expression. In summary, our data demonstrates that dBcAMP treatment increases [1-(14)C]20:4n-6 uptake in astrocytes and this increase appears to be due to increased expression of Acsl3 and Acsl4 coupled with a reduction in Acot7 expression.
Influence over Estrogen Dose Taken by Psychological Intervention for Climacteric Syndrome

Objective To investigate influence over the estrogen dose taken by grass-roots women with the climacteric syndrome on psychological intervention.Methods 72 patients diagnosed as moderate to severe climacteric syndrome were randomly divided into two groups.Experimental group,36 cases,daily doses of premarin 0.3 mg and psychological intervention;Control group,36 cases,daily doses of 0.625 mg premarin.Evaluate both groups six months later.Results Symptoms of both experimental group and control group improved significantly,there′s no significant difference between them(P0.05).Conclusion Psychological interventions could reduce the estrogen dose taken by patients with the climacteric syndrome.
Urolithiasis and Race: Another Viewpoint

AbstractWe describe 193 consecutive individuals with documented urolithiasis in a military population. In contrast to other reports, the prevalence of stone disease was nearly identical in white and black patients. This unique black population refutes the concept that urinary calculi are rare in blacks.
A Computational Investigation Predicts Mechanisms of Subcellular cAMP Compartmentation

For more than 30 years, subcellular compartmentation of the ubiquitous second messenger cAMP has been proposed as a mechanism to explain the distinct cAMP-mediated functional responses that occur after activation of various cell surface receptors. To date, the mechanism of compartmentation is still unknown. One possible mechanism of cAMP compartmentalization is specific localization of phosphodiesterases (PDEs), which degrade cAMP and create a functional barrier to the diffusion of cAMP. In order to assess the plausibility of this mechanism, we developed computational models to represent the subcellular sarcomeric spaces of a cardiac myocyte at varying resolutions. The models include a 2-dimensional continuum model of a subcellular compartment spanning the space between T-tubules of a cardiac sarcomere, a 3-dimensional stochastic model of cAMP diffusion in a microdomain using MCell (mcell.org), and a reduced 1-dimensional continuum model that can be solved analytically. We used these models to predict the contributions of various mechanisms to subcellular cAMP microdomains. We tested the hypothesis that phosphodiesterases act as functional barriers to diffusion, creating discrete cAMP signaling domains. We also used the models to predict the effect of a range of experimentally measured diffusion rates on cAMP compartmentation. Predictions from all the models concurred: Under realistic conditions phosphodiesterases were insufficient to generate cAMP gradients. This prediction persisted even with the slowest measured cAMP diffusion rate. Our model simulations suggest that additional mechanisms contribute to cAMP gradients occurring in submicroscopic cellular domains. Additional experimental studies will be needed to understand the contribution of factors required to coordinate spatio-temporal distribution of cAMP at the subcellular level.
Marijuana Use Among Young Black Men Who Have Sex With Men and the HIV Care Continuum: Findings From the uConnect Cohort.

ABSTRACTBackground: Young Black men who have sex with men (YBMSM) are at highest risk for HIV seroconversion in the United States. Successful movement through the HIV care continuum is an important intervention for limiting onwards HIV transmission. Objective: Little data exists on how substances most commonly used by YBMSM, such as marijuana, are related to the HIV continuum, which represents the primary aim of this study. Methods: A cohort of YBMSM (n = 618) was generated through respondent-driven sampling. Frequency of marijuana use and marijuana use as a sex-drug were assessed across the HIV care continuum using weighted logistic regression models. Results: Study participants reported more intermittent marijuana use (n = 254, 56.2%) compared to heavy use (n = 198, 43.8%). Our sample contained 212 (34.3%) HIV seropositive participants of which 52 (24.5%) were unaware of their HIV positive status. Study participants who were heavy marijuana users were more likely to be unaware of their HIV seropositive ...
Pipelining and Clocking of High Performance Synchronous Digital Systems

This chapter discusses the effects of pipelining on the performance of high speed synchronous digital systems. In particular, the tradeoff between clock frequency and latency is described in terms of the circuit characteristics of a pipelined data path [1,2]. The design of the clock distribution network synchronizing the signal flow between each data path can significantly affect system performance. Timing characteristics of the clock distribution network are described in terms of how system performance can be either enhanced or degraded. A design paradigm relating latency and clock frequency as a function of the level of pipelining is developed for studying the performance of a synchronous system. This perspective permits the development of design equations for constrained and unconstrained design problems which describe these performance parameters in terms of the delays of the logic, interconnect, and registers, the nature of the clock distribution network, and the number of logic stages.
Development of Tree and Understory Vegetation in Young Douglas-Fir Plantations in Western Oregon

The prevalence of young even-aged Douglas-fir (Pseudotsuga menziesii) stands in Oregon and Washington has led to concerns about a landscape being dominated by stands in the stem exclusion phase. In this context, our study documented the development of two aspects important for the diversity of plant and wildlife habitat: tree characteristics and understory vegetation. Using a chronosequence approach, we measured conditions in 39 plantations ranging from 6 to 20 years. Results confirmed intuitive trends, but the quantification indicated that some of these trends develop earlier than commonly assumed. Tree growth in young stands was positively related to stand density, but this trend reversed fairly early. Crown characteristics were influenced very early by stand density, indicating that maintaining a long-lived crown in typical plantations can only be accomplished by lowering stand density through precommercial thinning. Understory herb cover was reduced throughout time, while shrub cover increased. Species compositions were quite complex, with an initial strong presence of invader species and later dominance of species usually associated with mature forests; however, there were many exceptions and early successional species were still present after 20 years. The study showed that this early stage is very complex, that the dynamics vary for different characteristics, and that a finer resolution of the stand initiation stage may be warranted for plantations. West. J. Appl. For. 21(2):94–101.
A Study of Fruit Reachability in Orchard Trees by Linear-Only Motion

Abstract: Robotic fruit harvesters typically utilize multiple-degree-of-freedom arms, often kinematically redundant. The hypothesis is that as branches constrain fruit reachability, redundancy is necessary to navigate through branches and reach fruits inside the canopy. Modern commercial orchards increasingly adopt trees of SNAP architectures (Simple, Narrow, Accessible, and Productive). This paper presents a simulation study on linear fruit reachability (LFR) on high-density, trellised pear trees; linear only motion was used to reach the fruits. Results based on digitized geometric tree models and fruit locations showed that 91.1% of the fruits were reachable after three “harvesting passes” with proper approach angles.
On the Local Super-Linear Convergence of a Matrix Secant Implementation of the Variable Metric Proximal Point Algorithm for Monotone Operators

Interest in the variable metric proximal point algorithm (VMPPA) is fueled by the desire to accelerate the local convergence of the proximal point algorithm without requiring the divergence of the proximation parameters. In this paper, the local convergence theory for matrix secant versions of the VMPPA is applied to a known globally convergent version of the algorithm. It is shown under appropriate hypotheses that the resulting algorithms are locally super-linearly convergent when executed with the BFGS and the Broyden matrix secant updates. This result unifies previous work on the global and local convergence theory for this class of algorithms. It is the first result applicable to general monotone operators showing that a globally convergent VMPPA with bounded proximation parameters can be accelerated using matrix secant techniques. This result clears the way for the direct application of these methods to constrained and non-finite-valued convex programming. Numerical experiments are included illustrating the potential gains of the method and issues for further study.
Effective energy for (2+1)-dimensional QED with semilocalized static magnetic fields: A solvable model

We evaluate the exact (2+1)-dimensional QED effective energy for charged spin-0 and spin-1/2 fields in the presence of a family of static magnetic field profiles localized in a strip of width \ensuremath{\lambda}. The exact result yields an infinite set of relations between the terms in the derivative expansion of the effective energy for a general magnetic field. Upon addition of the standard Maxwell magnetostatic energy, the minimum energy configuration at fixed flux corresponds to a uniform magnetic field.
The Curry/Trump Split in Tax Reform

This is a follow-up to my SSRN post on December 6, 2017 of my Tax Notes article: Tax Reform: Taxing Trump and Curry Under the Republican Plan, Tax Notes, Vol 157, November 2017. The article discusses the House Republican version of the Tax Cut and Jobs Act (TCAJA), which adopted a maximum 25% rate on certain business income of pass-through entities. In an effort to sell the provision, the House Republicans compared the tax treatment of Stephen Curry, a star professional basketball player, who would not qualify for the 25% rate, to Steve of “Steve’s Bike Shop,” who would be entitled to the 25% rate. Apparently, the House Republicans used Curry because he got into a fight with President Trump over Curry’s decision not to visit the White House in connection with a celebration of his team’s NBA championship. The article argued that (1) the comparison of Curry to Steve is bogus, and (2) the real comparison is of Curry to President Trump. The article (1) showed that under the 25% provision President Trump would receive a “huge” tax break compared to Curry, and (2) argued that this 25% rate is bad tax policy and should be stricken from the TCAJA, thus taxing both Curry and President Trump at the same maximum rate. The title to the attached Letter to the Editor of Tax Notes is The Curry/Trump Split in Tax Reform, Tax Notes, page 151, Jan.1, 2018, and it compares the treatment of President Trump and Curry under Section 11011 of the Final TCAJA. This provision adds Section 199A to the Code, which provides, as a substitute for the 25% maximum tax in the House bill, a deduction of 20% of certain pass-through income. The Letter (1) demonstrates how the Final TCAJA continues to provide President Trump a “huge” tax break compared to Curry, and (2) asserts that a future Congress will repeal it because the disparate treatment is patently unsound from a tax policy perspective.
Fatigue Design with Additive Manufactured Metals: Issues to Consider and Perspective for Future Research

Abstract Additive manufacturing (AM) is a state of the art technology enabling fabrication of complex geometries, in addition to providing other advantages as compared to the traditional subtractive manufacturing methods. However, a wide variety of factors significantly influence fatigue behavior and structural performance of components made of AM metals. In addition to the fabrication process parameters, these include the effects of build direction, surface roughness, residual stresses, and heat treatment, and multiaxial stress states. At the microstructural level, defects such as pores and lack of fusion particles, as well as other microstructural features affect the behavior. In this paper, first a brief review of the aforementioned factors affecting the fatigue behavior will be presented. Then some experimental multiaxial fatigue data for selective laser melting (SLM), which is a powder bed fusion (PBF) metal AM process, of a common Ti alloy (Ti-6Al-4V) with applications in many industries are presented and discussed. The effects of surface finish, heat treatment, and stress state will be evaluated, as well as failure mechanisms in different life regimes and the role of defects. Finally, some additional factors that must be considered before wide acceptance of the AM technology in critical load bearing applications will be addressed.
The Sensitivity of Clinician Diagnosis of Sepsis in Tertiary and Community-Based Emergency Settings.

Objectives To assess whether the risk of missed clinician diagnosis of pediatric sepsis requiring care in the intensive care unit (ICU) was greater in community vs tertiary pediatric emergency care settings with sepsis pathways. Study design An observational cohort study in a tertiary pediatric emergency department (ED) staffed by pediatric emergency physicians and 4 affiliated community pediatric ED/urgent care sites staffed by general pediatricians. Use of an institutional sepsis order set or pathway was considered clinician diagnosis of sepsis. Risk of missed diagnosis was compared for 2 outcomes: suspected infection plus ICU admission (sepsis-ICU) and suspected infection plus vasoactive agent/positive-pressure ventilation (sepsis-VV). Results From January 1, 2014 to December 31, 2015, there were 141 552 tertiary and 139 332 community emergency visits. Clinicians diagnosed sepsis in 1136 visits; median age was 5.7 (2.4, 12.0) years. In the tertiary ED, there were 306 sepsis-ICU visits (0.2%) and 112 sepsis-VV visits (0.08%). In community sites, there were 46 sepsis-ICU visits (0.03%) and 20 sepsis-VV visits (0.01%). The risk of missed diagnosis in community vs tertiary sites was significantly greater for sepsis-ICU (relative risk 4.30, CI 2.15-8.60) and sepsis-VV (relative risk 14.0, CI 2.91-67.24). Sensitivity for sepsis-ICU was 94.4% (91.3%-96.5%) at the tertiary site and 76.1% (62.1%-86.1%) at community sites. Conclusions The risk of missed diagnosis of sepsis-ICU was greater in community vs tertiary emergency care settings despite shared pathways and education, but with differences in resources, providers, and sepsis incidence. More research is needed to optimize diagnostic approaches in all settings.
The Case of Oxidative Folding of Ribonuclease A: Factors Impacting Fold Maturation of ER-Processed Proteins

Proteins that are membrane-bound or secreted outside the cell often possess disulfide bonds. The maturation of such proteins is termed oxidative protein folding and takes place within the endoplasmic reticulum (ER) of eukaryotic cells prior to their export. The events that comprise oxidative folding are complex. A variety of intrinsic and extrinsic factors finely orchestrate the formation of a biologically viable molecule almost from the time of its genesis in the ribosome. This chapter recapitulates our current understanding of factors impacting fold maturation of ER-processed proteins which emerges from a large number of in vitro regeneration experiments performed in a number of laboratories on several small single-domain disulfide bond-containing proteins. The focus here is on advances made in our understanding of oxidative folding through studies on the folding pathways of bovine pancreatic ribonuclease A which were primarily undertaken by the Scheraga laboratory over 30 years. In addition, laboratory techniques and biophysical and biochemical manipulations which facilitate the study of oxidative protein folding are also discussed.
Strategic Petroleum Reserves

Strategic petroleum reserves, also referred to as strategic petroleum stocks, are quantities of crude oil or petroleum products held either to facilitate draw downs to reduce the economic impacts of crude oil supply disruptions or to deter purposeful reductions in crude oil supply for political ends. They reduce the vulnerability of the world economy, especially the economies of petroleum importers, to the adverse consequences of sudden and steep price increases resulting from the removal of substantial quantities of crude oil supply from the world market. They make purposeful reductions in crude oil exports for political purposes less attractive by increasing the quantities that must be withheld to inflict any threatened level of harm on petroleum importers. In these ways, strategic petroleum reserves reduce the risks to the world economy associated with reliance on geographically concentrated crude oil supplies.
Reperfusion of Ischemic Brain: Why and Why Not!

Since the time of William Harvey, physiologists, anatomists, and clinicians alike have viewed the heart and circulatory system as supporting actors whose role it was to provide blood to the various organs of the body. Arguably the principal organ supplied is the brain, which controls the perceptions, thoughts, and actions of the body. Clearly, the raison d’etre of the arteries coursing to the brain is to supply blood which carries fuel, mainly sugar and oxygen, to nervous system structures which cannot function without it. When an artery is blocked, even temporarily, the brain is deprived of fuel and stops working just as a car would without gas. If fuel is lacking for long enough, the brain wilts, softens, and dies. Some components seem more vulnerable to the lack of fuel supply and die before others.
Results of Recent Applications of Raman Scattering to Research Problems at NASA Langley Research Center

Results presented at the Raman Workshop illustrated work in progress at the Langley Research Center to utilize Raman scattering as a flow field diagnostic tool with emphasis on fluid mechanics and aerodynamics research applications. Results of two experiments conducted by Mr. M. E. Hillard were shown.
Preoperative opioid medication use negatively affect health related quality of life after total knee arthroplasty

Abstract Background Opioids are commonly prescribed to treat patients suffering from painful knee arthritis. However, the opioid epidemic in the United States constitutes a major public health concern. This study aims to characterize the effect of preoperative opioid use on patient-reported outcome measures (PROMs) after total knee arthroplasty (TKA). Methods PROMs collected from patients undergoing TKA were reviewed. We identified two matched cohorts: (1) 30 patients who used opioids preoperatively and (2) 137 patients who did not use opioids preoperatively. The non-opioid cohort was carefully selected to match the opioid cohort. Statistical analyses were performed to determine the difference in demographics, PROMs, length of stay, disposition and co-morbidities between the two cohorts. Results The non-opioid users had significant improvement in both EuroQol5D (EQ-5D) PROMs and visual analogy scale (VAS) scores postoperatively (p Conclusion Our results demonstrated that TKA patients with preoperative opioid use had significantly lower VAS scores and trends of lower UCLA and EQ-5D scores postoperatively compared to non-opioid patients, suggesting the use of opioid medications prior to TKA negatively affects patient reported outcomes following surgery. The current findings provide useful clinical information that can be used in counseling patients prior to undergoing TKA.
Introduction to semiconductor processing: Fabrication and characterization of p-n junction silicon solar cells

We describe an upper-division undergraduate physics laboratory experiment that integrates the fabrication and characterization of a p-n junction in silicon. Under standard illumination, this p-n junction exhibits the photovoltaic effect as well as the typical diode rectification behavior when measured in the dark. This experiment introduces students to the physics of solar photovoltaics from the perspective of participating in the fabrication process. Procedures, experimental strategies, and typical student measurement results are presented. This low-cost, engaging, and effective lab can be adapted to undergraduate physics courses at various institutes.
Correlation network analysis shows divergent effects of a long-term, high-fat diet and exercise on early stage osteoarthritis phenotypes in mice.

Abstract Background Obesity increases knee osteoarthritis (OA) risk through metabolic, inflammatory, and biomechanical factors, but how these systemic and local mediators interact to drive OA pathology is not well understood. We tested the effect of voluntary running exercise after chronic diet-induced obesity on knee OA-related cartilage and bone pathology in mice. We then used a correlation-based network analysis to identify systemic and local factors associated with early-stage knee OA phenotypes among the different diet and exercise groups. Methods Male C57BL/6J mice were fed a defined control (10% kcal fat) or high fat (HF) (60% kcal fat) diet from 6 to 37 weeks of age. At 25 weeks, one-half of the mice from each diet group were housed in cages with running wheels for the remainder of the study. Histology, micro computed tomography, and magnetic resonance imaging were used to evaluate changes in joint tissue structure and OA pathology. These local variables were then compared to systemic metabolic (body mass, body fat, and glucose tolerance), inflammatory (serum adipokines and inflammatory mediators), and functional (mechanical tactile sensitivity and grip strength) outcomes using a correlation-based network analysis. Diet and exercise effects were evaluated by two-way analysis of variance. Results An HF diet increased the infrapatellar fat pad size and posterior joint osteophytes, and wheel running primarily altered the subchondral cortical and trabecular bone. Neither HF diet nor exercise altered average knee cartilage OA scores compared to control groups. However, the coefficient of variation was ≥25% for many outcomes, and some mice in both diet groups developed moderate OA (≥33% maximum score). This supported using correlation-based network analyses to identify systemic and local factors associated with early-stage knee OA phenotypes. In wheel-running cohorts, an HF diet reduced the network size compared to the control diet group despite similar running distances, suggesting that diet-induced obesity dampens the effects of exercise on systemic and local OA-related factors. Each of the 4 diet and activity groups showed mostly unique networks of local and systemic factors correlated with early-stage knee OA. Conclusion Despite minimal group-level effects of chronic diet-induced obesity and voluntary wheel running on knee OA pathology under the current test durations, diet and exercise substantially altered the relationships among systemic and local variables associated with early-stage knee OA. These results suggest that distinct pre-OA phenotypes may exist prior to the development of disease.
Complete Diastereocontrol in Intramolecular 1,3-Dipolar Cycloadditions of 2-Substituted 5-Hexenyl and 5-Heptenyl Nitrones: Application to the Synthesis of the beta-Lactam Antibiotic 1beta-Methylthienamycin.

The diastereoselectivity of intramolecular 1,3-dipolar cycloadditions of 2-substituted 5-hexenyl and 5-heptenyl nitrones to give 6-substituted and 3,6-disubstituted perhydrocyclopenta[c]isoxazoles has been investigated. An alkyl or aryl substituent at C2 completely controls the stereochemistry of the ring juncture and, in the case of the 5-heptenyl systems, also the stereochemistry of the 3-methyl group. Thus one stereocenter controls the formation of the other three to give a product with four contiguous stereocenters. The use of an ethylene ketal substituent in these systems allows the reaction to be carried out at much lower temperatures, an example of the gem-dialkoxy effect. This cycloaddition process has been used in an efficient formal total synthesis of the potent β-lactam antibiotic, 1β-methylthienamycin.
Retinoid X receptor agonist LG100268 modulates the immune microenvironment in preclinical breast cancer models

Despite numerous therapeutic advances in the past decade, breast cancer is expected to cause over 42,000 deaths in the United States in 2019. Breast cancer had been considered an immunologically silent tumor; however recent findings suggest that immune cells play important roles in tumor growth even in the breast. Retinoid X receptors (RXRs) are a subclass of nuclear receptors that act as ligand-dependent transcription factors that regulate a variety of cellular processes including proliferation and differentiation; in addition, they are essential for macrophage biology. Rexinoids are synthetic molecules that bind and activate RXRs. Bexarotene is the only rexinoid approved by the FDA for the treatment of refractory cutaneous T-cell lymphoma. Other more-potent rexinoids have been synthesized, such as LG100268 (LG268). Here, we report that treatment with LG 268, but not bexarotene, decreased infiltration of myeloid-derived suppressor cells and CD206-expressing macrophages, increased the expression of PD-L1 by 50%, and increased the ratio of CD8/CD4, CD25 T cells, which correlates with increased cytotoxic activity of CD8 T cells in tumors of MMTV-Neu mice (a model of HER2-positive breast cancer). In the MMTV-PyMT murine model of triple negative breast cancer, LG268 treatment of established tumors prolonged survival, and in combination with anti-PD-L1 antibodies, significantly (p = 0.05) increased the infiltration of cytotoxic CD8 T cells and apoptosis. Collectively, these data suggest that the use of LG268, a RXR agonist, can improve response to immune checkpoint blockade in HER2+ or triple-negative breast cancer.
A non-activating diluent to prolong in vitro viability of Apis mellifera spermatozoa: Effects on cryopreservation and on egg fertilization

Abstract A non-activating semen diluent does not cause motility or acrosomal reaction or capacitate the sperm cell. The effects of such a diluent on the viability of honey bee spermatozoa stored in ambient conditions were assessed 60 days pre-cryopreservation and 24 h post-cryopreservation. Seven variations of a Tris-based non-activating diluents (FEM1 – FEM7) were compared to samples treated with conventional activating diluent and untreated semen. Semen viability (membrane integrity) was assessed after short- and long-term storage at 14.0 ± 0.2 °C. The non-activating medium FEM7 contained more viable spermatozoa than the activating medium, 24 h after cryopreservation (67.6 ± 10.9% and ~4%, respectively). After 60 days, 22.0 ± 7.8% of spermatozoa was viable in non-activating medium versus 0.0 and 60.8 ± 12.3%, in conventional media and untreated controls, respectively. Hence FEM7 was used to cryopreserve bee semen and subsequently inseminate honey bee queens. The quality of brood produced by the queens was assessed 30–60 days after insemination. The percentage of worker-bee offspring (produced from successfully fertilized eggs) was ~75% for both the non-activating medium and the conventional extender medium. Our results indicate that a non-activating medium possesses significant advantage over the conventional activating medium if the semen requires storage after treatments such as cryopreservation. The percentage of female offspring (from fertilized eggs) produced by queens inseminated with semen diluted in either the activating or non-activating medium did not differ from one another.
The Brief Case: Rat Bite Fever from a Kiss.

A 20-year-old otherwise healthy male presented to his primary care clinic with a 1-week history of fevers, rash, and polyarthralgias affecting his knees, elbows, and wrists that began 5 days following an acute diarrheal illness. In the clinic he was febrile to 38.5°C with a petechial rash
A Retrospective Mixed Longitudinal Study of Tooth Formation in Children With Clefts.

Objective:To test for systematic age changes in cleft children based on dental age.Design:Retrospective case–control longitudinal study.Setting:One orthodontic solo practice.Patients:Nonsyndromic, ...
Development and implementation of an e-visit objective structured clinical examination to evaluate student ability to provide care by telehealth.

ABSTRACT The provision of care through telehealth is emerging as a strategy to meet the challenges of a changing health care system; however, educational experiences associated with telehealth are limited in nursing curricula. In 2018, the National Organization of Nurse Practitioner Faculties (NONPF) recommended incorporating telehealth modalities in nurse practitioner education, including clinical skills assessment. Objective structured clinical examinations (OSCEs) have been used as formative and summative evaluations of health science students since the 1970s to assess application of didactic learning in clinical practice. Although few studies have investigated integrating OSCEs, virtual simulation, or telehealth in distance education, those that exist demonstrate significant improvement in clinical decision making. This article describes the development and implementation of an OSCE at a large Midwestern university delivered via web conferencing to evaluate online family nurse practitioner (FNP) students' abilities to deliver care using telecommunication technology. An e-visit notification listing the types of symptoms available for treatment by telehealth served as a content list. Students completed a 15-minute e-visit assessing and managing the care of a standardized patient presenting with a recent onset of dysuria. The video conference included the FNP student, standardized patient, and faculty evaluating in real time using a rubric incorporating NONPF competencies for telehealth. Structured group debrief, an integral part of the learning process in clinical simulations, followed the e-visit OSCE using free conference calling. Faculty and student feedback and evaluations of this summative OSCE implemented for three cohort groups (103 students) positively reflect the importance of preparing students for practice in a transformed health care system.
Optical coherence computed tomography

We proposed a novel time-resolved optical tomography, optical coherence computed tomography. It married the key concepts of time-resolved diffuse optical tomography and optical coherence tomography. Both ballistic and multiple-scattered photons were measured at multiple source-detection positions by low-coherence interferometry. It measures the reemitted light with a temporal resolution of 56 femtoseconds, which is much better than the resolution of conventional time-resolved detection systems. A light-tissue interaction model was established using the time-resolved Monte Carlo method. The optical properties were then reconstructed by solving the inverse time-resolved radiative transport problem under the first Born approximation. Our initial results showed the potential of this technology to bridge the gap between diffuse optical tomography and optical coherence tomography.
Why Restrain Alienation

In her informative article, Inalienability and the Theory of Property Rights,' Susan Rose-Ackerman raises anew one persistent question that has worked itself into the fabric of our general law: Why should there be any restraints on the alienation of property? As stated the question is an extremely broad one. The right of alienation, as part of the bundle of property rights, is set in opposition to the rights of possession and use. The types of property to which it can extend are real and personal, tangible and intangible. Each type of property may be alienated in a number of different ways, such as by sale, hire, mortgage, lease, bail, or pledge. These various forms of alienation in turn may be restrained in many ways. The restraints may be whole or partial; they may be by common law rule or by public regulation; alienation may be subject to an absolute prohibition, or it may be exercisable only upon the payment of money. As the possible range of restraints on alienation is very broad, it is important to order the inquiry so as to exhibit its essential features. This Article first seeks to explain why the right of alienation is a normal incident of private ownership. Thereafter it seeks to examine the principled reasons for limiting the right. These justifications in turn fall into two main groups. The first set is concerned with the practical control of externalities. These may take the form of aggression against third parties, the overexploitation of the common pool, or the exploitation of infants and insane persons. Alternatively, restraints on alienation may be used to redress some asserted distributional weakness within the present allocation of rights. My central thesis is that the first justification is sound, but that the second is not. The proper office for restraints on alienation is to provide indirect control over external harms when direct means of control are ineffective to the task. In working through this analysis I start from the assumption that the core function of the law is to protect all persons and their property against the force and fraud of another. There is no doubt in my view that this simple view of entitlements between persons lies at the heart of most of our legal system, both as it developed at common law, and as it has come to be modified by statute. It is simply inconceivable to ac-
SARS-CoV-2 infection reduces Krüppel-Like Factor 2 in human lung autopsy

Acute respiratory distress syndrome (ARDS) occurred in ~12% of hospitalized COVID-19 patients in a recent New York City cohort. Pulmonary endothelial dysfunction, characterized by increased expression of inflammatory genes and increased monolayer permeability, is a major component of ARDS. Vascular leak results in parenchymal accumulation of leukocytes, protein, and extravascular water, leading to pulmonary edema, ischemia, and activation of coagulation associated with COVID-19. Endothelial inflammation further contributes to uncontrolled cytokine storm in ARDS. We have recently demonstrated that Kruppel-like factor 2 (KLF2), a transcription factor which promotes endothelial quiescence and monolayer integrity, is significantly reduced in experimental models of ARDS. Lung inflammation and high-tidal volume ventilation result in reduced KLF2, leading to pulmonary endothelial dysfunction and acute lung injury. Mechanistically, we found that KLF2 is a potent transcriptional activator of Rap guanine nucleotide exchange factor 3 (RAPGEF3) which orchestrates and maintains vascular integrity. Moreover, KLF2 regulates multiple genome-wide association study (GWAS)-implicated ARDS genes. Whether lung KLF2 is regulated by SARS-CoV-2 infection is unknown. Here we report that endothelial KLF2 is significantly reduced in human lung autopsies from COVID-19 patients, which supports that ARDS due to SARS-CoV-2 is a vascular phenotype possibly attributed to KLF2 down-regulation. We provide additional data demonstrating that KLF2 is down-regulated in SARS-CoV infection in mice.
Associations between PM2.5 metal components and QT interval length in the Normative Aging Study.

Abstract Background Several studies have found associations between increases in QT interval length, a marker of cardiac electrical instability, and short-term fine particulate matter (PM2.5) exposures. To our knowledge, this is the first study to examine the association between specific PM2.5 metal components and QT interval length. Methods We measured heart-rate corrected QT interval (QTc) duration among 630 participants in the Normative Aging Study (NAS) based in Eastern Massachusetts between 2000 and 2011. We utilized time-varying linear mixed-effects regressions with a random intercept for each participant to analyze associations between QTc interval and moving averages (0–7 day moving averages) of 24-h mean concentrations of PM2.5 metal components (vanadium, nickel, copper, zinc and lead) measured at the Harvard Supersite monitoring station. Models were adjusted for daily PM2.5 mass estimated at a 1 km × 1 km grid cell from a previously validated prediction model and other covariates. Bayesian kernel machine regression (BKMR) was utilized to assess the overall joint effect of the PM2.5 metal components. Results We found consistent results with higher lead (Pb) associated with significant higher QTc intervals for both the multi-pollutant and the two pollutant (PM2.5 mass and a PM2.5 component) models across the moving averages. The greatest effect of lead on QTc interval was detected for the 4-day moving average lead exposure. In the multi-pollutant model, each 2.72 ng/m3 increase in daily lead levels for a 4-day moving average was associated with a 7.91 ms (95% CI: 3.63, 12.18) increase in QTc interval. In the two-pollutant models with PM2.5 mass and lead, each 2.72 ng/m3 increase in daily lead levels for a 4-day moving average was associated with an 8.50 ms (95% CI: 4.59, 12.41) increase in QTc interval. We found that 4-day moving average of copper has a negative association with QTc interval when compared to the other PM2.5 metal components. In the multi-pollutant model, each 1.81 ng/m3 increase in daily copper levels for a 4-day moving average was associated with an −3.89 ms (95% CI: -6.98, −0.79) increase in QTc interval. Copper's essential function inside the human body could mediate its cardiotoxicity on cardiac conductivity and explain why we found that copper in comparison to the other metals was less harmful for QTc interval. Conclusions Exposure to metals contained in PM2.5 are associated with acute changes in ventricular repolarization as indicated by QT interval characteristics.