Modeling Surface Vibrations and Their Role in Molecular Adsorption: A Generalized Langevin Approach.

The atomic vibrations of a solid surface can play a significant role in the reactions of surface-bound molecules, as well as their adsorption and desorption. Relevant phonon modes can involve the collective motion of atoms over a wide array of length scales. In this paper, we demonstrate how the generalized Langevin equation can be utilized to describe these collective motions weighted by their coupling to individual sites. Our approach builds upon the generalized Langevin oscillator (GLO) model originally developed by Tully. We extend the GLO by deriving parameters from atomistic simulation data. We apply this approach to study the memory kernel of a model platinum surface and demonstrate that the memory kernel has a bimodal form due to coupling to both low-energy acoustic modes and high-energy modes near the Debye frequency. The same bimodal form was observed across a wide variety of solids of different elemental compositions, surface structures, and solvation states. By studying how these dominant modes depend on the simulation size, we argue that the acoustic modes are frozen in the limit of macroscopic lattices. By simulating periodically replicated slabs of various sizes, we quantify the influence of phonon confinement effects in the memory kernel and their concomitant effect on simulated sticking coefficients.

Ileal neobladder adenocarcinoma occurring twenty-five years post ileocystoplasty: a case report.

De-tubularised ileum is one of the most common segments used for augmentation cystoplasty. It is associated with complications such as metabolic disturbances, recurrent urinary tract infections, and stone formation. However, adenocarcinoma arising in an augmented bladder is a rare occurrence. We report a 37-year-old female, case of ileocystoplasty 25 years ago due to a thimble bladder (genitourinary tuberculosis) who presented with hematuria for one month. Cystoscopy showed bladder mass in the transposed ileal segments. The patient underwent transurethral resection of the bladder lesion, and the histopathology was suggestive of adenocarcinoma of the ileum. Subsequently, she underwent anterior pelvic exenteration and post-operative recovery was uneventful. The 6-month follow-up showed that the patient was asymptomatic without recurrence. In conclusion, even though adenocarcinoma in the ileal neobladder is rare, life-long with close follow-up with routine cytologic, radiologic, and cystoscopic evaluation for early cancer detection and treatment at an early stage is crucial.

Calculation of Self, Corrected, and Transport Diffusivities of Isopropyl Alcohol in UiO-66.

The UiO-6x family of metal-organic frameworks has been extensively studied for applications in chemical warfare agent (CWA) capture and destruction. An understanding of intrinsic transport phenomena, such as diffusion, is key to understanding experimental results and designing effective materials for CWA capture. However, the relatively large size of CWAs and their simulants makes diffusion in the small-pored pristine UiO-66 very slow and hence impractical to study directly with direct molecular simulations because of the time scales required. We used isopropanol (IPA) as a surrogate for CWAs to investigate the fundamental diffusion mechanisms of a polar molecule within pristine UiO-66. IPA can form hydrogen bonds with the µ3-OH groups bound to the metal oxide clusters in UiO-66, similar to some CWAs, and can be studied by direct molecular dynamics simulations. We report self, corrected, and transport diffusivities of IPA in pristine UiO-66 as a function of loading. Our calculations highlight the importance of the accurate modeling of the hydrogen bonding interactions on diffusivities, with about an order of magnitude decrease in diffusion coefficients when the hydrogen bonding between IPA and the µ3-OH groups is included. We found that a fraction of the IPA molecules have very low mobility during the course of a simulation, while a small fraction are highly mobile, exhibiting mean square displacements far greater than the ensemble average.

Stress, intertemporal choice, and mitigation behavior during the COVID-19 pandemic.

Delayed gratification is an important focus of research, given its potential relationship to forms of behavior, such as savings, susceptibility to addiction, and pro-social behaviors. The COVID-19 pandemic may be one of the most consequential recent examples of this phenomenon, with people's willingness to delay gratification affecting their willingness to socially distance themselves. COVID-19 also provides a naturalistic context by which to evaluate the ecological validity of delayed gratification. This article outlines four large-scale online experiments (total N = 12, 906) where we ask participants to perform Money Earlier or Later (MEL) decisions (e.g., $5 today vs. $10 tomorrow) and to also report stress measures and pandemic mitigation behaviors. We found that stress increases impulsivity and that less stressed and more patient individuals socially distanced more throughout the pandemic. These results help resolve longstanding theoretical debates in the MEL literature as well as provide policymakers with scientific evidence that can help inform response strategies in the future. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Concomitant Vaginal Laceration and Urinary Bladder Injury With Pubic Diastasis: A Case Report on a Rare Complication During Obstructed Labor.

A serious uro-obstetric emergency is the concurrent rupture of the uterine and urine bladder following a protracted difficult delivery. In the absence of circumstances that would make the bladder more likely to cling to the lower uterine segment, the involvement of the urinary bladder in a primigravida is unique and relatively infrequent. We discuss a case of a 21-year-old patient who had an obstructed labor complicated with bladder and vaginal injury. At laparotomy, we found a pubic bone diastasis, a vaginal injury, and a bladder injury at the urethrovesical junction. As a result, bladder neck repair with urethrovesical anastomosis and vaginal repair with an external fixator were carried out for pubic bone diastasis.

Retained ureteral stents, an avoidable source of morbidity: 10 years´ experience from a single tertiary care centre.

Introduction: ureteral stents are used in managing various urological conditions. When these stents are left indwelling for a prolonged time, it results in complications like stent migration, fragmentation, and encrustation. The aim of this retrospective observational study is to analyse the incidence, risk factors, and morbidity associated with retained ureteral stents. Methods: the retained/forgotten ureteral stents were defined as the stents with an indwelling period of more than six months. The records of all such patients from January 2010 to January 2020 were retrospectively reviewed. The primary reason for the placement of a stent, total indwelling time, the reason for prolonged indwelling time, and part(s) of the stent encrusted were retrospectively reviewed. Single/multistage endourological procedures were used to make the patients remove the retained stents and stone free. The type, number of procedures, and total number of sessions needed were noted. Results: data of 114 patients was reviewed retrospectively. Most patients presented with abdominal pain (62 patients, 54.4%), and dysuria (41 patients, 35.1%). An average of 1.7 sessions (range 1-4) were needed to make the patients' stent and stone free. During these sessions, single/multiple procedures (endoscopic/open/combined) were performed. Nine patients (7.9%) had permanent loss of renal unit function and who needed a nephrectomy. Poor compliance (45.6%), unawareness (35.1%), and misconception that the stent would last a lifetime (12.3%), were the most common reasons for retained ureteral stents. The incidence rate of retained stents fell from 1.1% to 0.5% after the "three steps" prevention check method was in-cooperated to ensure timely follow-up of the patients. Conclusion: retained ureteral stents are a significant source of morbidity, which is avoidable by ensuring timely removal. Sincere efforts should be made to make patients aware of an indwelling foreign body. Prevention is the best strategy.

The temporal dynamics of opportunity costs: A normative account of cognitive fatigue and boredom.

Cognitive fatigue and boredom are two phenomenological states that reflect overt task disengagement. In this article, we present a rational analysis of the temporal structure of controlled behavior, which provides a formal account of these phenomena. We suggest that in controlling behavior, the brain faces competing behavioral and computational imperatives, and must balance them by tracking their opportunity costs over time. We use this analysis to flesh out previous suggestions that feelings associated with subjective effort, like cognitive fatigue and boredom, are the phenomenological counterparts of these opportunity cost measures, instead of reflecting the depletion of resources as has often been assumed. Specifically, we propose that both fatigue and boredom reflect the competing value of particular options that require foregoing immediate reward but can improve future performance: Fatigue reflects the value of offline computation (internal to the organism) to improve future decisions, while boredom signals the value of exploration (external in the world). We demonstrate that these accounts provide a mechanistically explicit and parsimonious account for a wide array of findings related to cognitive control, integrating and reimagining them under a single, formally rigorous framework. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Persistent Mullerian Duct Syndrome: A Rare Case of an Adult Infertile Male with Bilateral Cryptorchidism.

BACKGROUND: Persistent mullerian duct syndrome (PMDS) is a very rare form of internal male pseudohermaphroditism in individuals who are phenotypically males with 46 XY karyotypes harboring internal female reproductive organs which are Mullerian derivatives. It occurs as a defect in the genes coding for the Mullerian inhibiting substance (MIS) or the anti Mullerian hormone (AMH) receptor, ultimately leading to failure of regression of Mullerian ducts. CASE PRESENTATION: A 29-year-old male with PMDS presented with complaints of primary infertility. Diagnosis was made with the help of high index of suspicion, radiological imaging, and karyotyping. Our patient underwent exploratory laparotomy with hysterectomy and bilateral orchidopexy. CONCLUSION: The purpose of this study was increasing awareness regarding rare entities and surgeons should have high clinical suspicion of PMDS when patient with bilateral undescended testis comes for the evaluation of primary infertility.

Using large-scale experiments and machine learning to discover theories of human decision-making.

Predicting and understanding how people make decisions has been a long-standing goal in many fields, with quantitative models of human decision-making informing research in both the social sciences and engineering. We show how progress toward this goal can be accelerated by using large datasets to power machine-learning algorithms that are constrained to produce interpretable psychological theories. Conducting the largest experiment on risky choice to date and analyzing the results using gradient-based optimization of differentiable decision theories implemented through artificial neural networks, we were able to recapitulate historical discoveries, establish that there is room to improve on existing theories, and discover a new, more accurate model of human decision-making in a form that preserves the insights from centuries of research.

Choosing an ideal second layer cover in snodgrass repair for various types of hypospadias.

OBJECTIVE: In this study, we aimed to assess the results of tunica vaginalis flap (TVF), dorsal preputial dartos flap (DPF), and spongioplasty alone as additional cover after neourethra formation in a Snodgrass repair for various types of hypospadias as per the selection criteria decided. MATERIAL AND METHODS: This was a non-randomized experimental study of 97 patients with primary hypospadias treated via Snodgrass repair using various second layers (tunica vaginalis flap, dorsal preputial dartos flap, and spongiosum alone) as per the selection criteria in a single center by a single surgeon. The outcome of the procedure was assessed in terms of cosmesis, chordee correction, urinary stream, and uroflowmetry. RESULTS: Of the 97 patients, we used dorsal preputial dartos flap in 42 (43.3%), tunica vaginalis in 38 (39.2%), and spongioplasty only in 17 (17.5%) for primary hypospadias. Urethrocutaneous fistula developed in four patients (three in DPF and one in the TVF groups). One patient each had skin necrosis, hematoma, and wound dehiscence in the DPF group. In the spongioplasty only group, one patient had meatal stenosis which was treated by meatoplasty after failing repeated periodic calibration. CONCLUSION: DPF should be preferably used for distal penile and TVF for mid and proximal penile hypospadias to ensure excellent result with minimum complications. Spongioplasty only as a second layer is sufficient to avoid the complications wherever it is thick and robust.

Congenital Cryptorchidism Masquerading as Traumatic Dislocation of Testis.

Traumatic dislocation of testis (TDT) is an uncommon event. During trauma, the cremasteric reflex can forcefully retract the testis out of the scrotal sac saving the testis from the injury. However, associated injuries in the form of skin degloving, penile avulsion, and amputation can be present. Early surgical intervention to locate and deposit the displaced testis to the scrotal sac is essential. We present a case of a 33-year-old man with bilateral congenital cryptorchidism who suffered blunt trauma to his genitalia following a road traffic injury. On presentation, based on a well-developed scrotum, it looked like a case of TDT. However, good history along with detailed physical and radiological evaluation helped us reach the correct diagnosis. TDT must be suspected in a case of blunt trauma to the genitalia when the scrotal sac (well-developed) is empty. This case report highlights the importance of detailed clinical and radiological evaluation in such cases.

Augmenting the Carbon Dioxide Uptake and Selectivity of Metal-Organic Frameworks by Metal Substitution: Molecular Simulations of LMOF-202.

Metal organic frameworks (MOFs) are promising porous materials for the adsorption of CO2. Here, we report the study of a luminescent MOF (LMOF), called LMOF-202. We have employed Grand Canonical Monte Carlo (GCMC) simulations to understand and explain the adsorption phenomena inside LMOF-202, and based on the phenomena happening at the molecular level, we have varied the metal ions in LMOF-202 to increase the CO2 affinity and selectivity of the material. We show that the CO2 adsorption capacity and selectivity can be increased by approximately 1.5 times at 1 bar and 298 K by changing the metal ion from Zn to Ba. We also report the feasibility of using this material to capture CO2 from flue gas under realistic conditions (1 bar and 298 K). This work shows that LMOF-202 merits further consideration as a carbon capture adsorbent.

Scale-free, programmable design of morphable chain loops of kilobots and colloidal motors.

Micron-scale robots require systems that can morph into arbitrary target configurations controlled by external agents such as heat, light, electricity, and chemical environment. Achieving this behavior using conventional approaches is challenging because the available materials at these scales are not programmable like their macroscopic counterparts. To overcome this challenge, we propose a design strategy to make a robotic machine that is both programmable and compatible with colloidal-scale physics. Our strategy uses motors in the form of active colloidal particles that constantly propel forward. We sequence these motors end-to-end in a closed chain forming a two-dimensional loop that folds under its mechanical constraints. We encode the target loop shape and its motion by regulating six design parameters, each scale-invariant and achievable at the colloidal scale. We demonstrate the plausibility of our design strategy using centimeter-scale robots called kilobots We use Brownian dynamics simulation to explore the large design space beyond that possible with kilobots, and present an analytical theory to aid the design process. Multiple loops can also be fused together to achieve several complex shapes and robotic behaviors, demonstrated by folding a letter shape "M," a dynamic gripper, and a dynamic pacman The material-agnostic, scale-free, and programmable nature of our design enables building a variety of reconfigurable and autonomous robots at both colloidal scales and macroscales.

Scaling up psychology via Scientific Regret Minimization.

Do large datasets provide value to psychologists? Without a systematic methodology for working with such datasets, there is a valid concern that analyses will produce noise artifacts rather than true effects. In this paper, we offer a way to enable researchers to systematically build models and identify novel phenomena in large datasets. One traditional approach is to analyze the residuals of models-the biggest errors they make in predicting the data-to discover what might be missing from those models. However, once a dataset is sufficiently large, machine learning algorithms approximate the true underlying function better than the data, suggesting, instead, that the predictions of these data-driven models should be used to guide model building. We call this approach "Scientific Regret Minimization" (SRM), as it focuses on minimizing errors for cases that we know should have been predictable. We apply this exploratory method on a subset of the Moral Machine dataset, a public collection of roughly 40 million moral decisions. Using SRM, we find that incorporating a set of deontological principles that capture dimensions along which groups of agents can vary (e.g., sex and age) improves a computational model of human moral judgment. Furthermore, we are able to identify and independently validate three interesting moral phenomena: criminal dehumanization, age of responsibility, and asymmetric notions of responsibility.

Impact of intrinsic framework flexibility for selective adsorption of sarin in non-aqueous solvents using metal-organic frameworks.

Molecular modeling of mixture adsorption in nanoporous materials can provide insight into the molecular-level details that underlie adsorptive separations. Modeling of adsorption often employs a rigid framework approximation for computational convenience. All real materials, however, have intrinsic flexibility due to thermal vibrations of their atoms. In this article, we examine quantitative predictions of the adsorption selectivity for a dilute concentration of a chemical warfare agent, sarin, from bulk mixtures with aqueous and non-aqueous (methanol, isopropyl alcohol) solvents using metal-organic frameworks (MOFs). These predictions were made in MOFs approximated as rigid and also in MOFs allowed to have intrinsic flexibility. Including framework flexibility appears to have important consequences for quantitative predictions of adsorption selectivity, particularly for sarin/water mixtures. Our observations suggest the intrinsic flexibility of MOFs can have a nontrivial impact on adsorption modeling of molecular mixtures, especially for mixtures containing polar species and molecules of different sizes.

Does repeat synthesis in materials chemistry obey a power law?

Finding examples where experimental measurements have been repeated is a powerful strategy for assessing reproducibility of scientific data. Here, we collect quantitative data to assess how often synthesis of a newly reported material is repeated in the scientific literature. We present a simple power-law model for the frequency of repeat syntheses and assess the validity of this model using a specific class of materials, metal-organic frameworks (MOFs). Our data suggest that a power law describes the frequency of repeat synthesis of many MOFs but that a small number of "supermaterials" exist that have been replicated many times more than a power law would predict. Our results also hint that there are many repeat syntheses that have been performed but not reported in the literature, which suggests simple steps that could be taken to greatly increase the number of reports of replicate experiments in materials chemistry.

Determining Diffusion Coefficients of Chemical Warfare Agents in Metal-Organic Frameworks.

Metal-organic frameworks (MOFs) have shown potential for selective capture of chemical warfare agents (CWAs). To determine characteristic adsorption times, the kinetics of CWA uptake in MOFs must be known. Here, we calculate diffusion coefficients of the CWA sarin and simulants in prototypical MOFs using classical molecular simulations. Sarin can diffuse throughout a one micrometer crystal in less than a second in MIL-47 and Cu-BTC, but this process takes more than 3 h in ZIF-8 and UiO-66. A simple estimate based on Knudsen diffusion is able to describe diffusion of sarin in MIL-47 but fails to do so in other MOFs. This work has implications in designing devices to detect and capture CWAs.

Effects of Intrinsic Flexibility on Adsorption Properties of Metal-Organic Frameworks at Dilute and Nondilute Loadings.

Molecular simulation of adsorption in nanoporous materials has become a valuable complement to experimental studies of these materials. In almost all cases, these simulations treat the adsorbing material as rigid. We use molecular simulations to examine the validity of this approximation for the adsorption in metal-organic frameworks (MOFs) that have framework flexibility without change in their unit cells because of thermal vibrations. All nanoporous materials are subject to this kind of framework flexibility. We examine the adsorption of nine molecules (CO2, CH4, ethane, ethene, propane, propene, butane, Xe, and Kr) and four molecular mixtures (CO2/CH4, ethane/ethene, propane/propene/butane, and Xe/Kr) in 100 MOFs at dilute and nondilute adsorption conditions. Our results show that single-component adsorption uptakes at nondilute conditions are only weakly affected by framework flexibility, but adsorption selectivities at both dilute and nondilute conditions can be significantly affected by flexibility. The most dramatic impacts of framework flexibility occur for adsorption uptake in the limit of dilute adsorption. These results suggest that the importance of including framework flexibility when attempting to make quantitative predictions of adsorption selectivity in MOFs and similar materials may have been underestimated in the past.

Predicting beta bursts from local field potentials to improve closed-loop DBS paradigms in Parkinson's patients.

Motor symptoms in Parkinson's disease (PD) correlate with an excess in synchrony in the beta frequency band (13-30Hz) of local field potentials recorded from basal ganglia circuits. Recent results have suggested that this abnormal activity arises as a result of changes in specific dynamical features of the underlying neural signatures. In particular, patterns of activity in the beta band have been shown to be structured in bursts of longer durations and higher amplitudes in untreated patients with PD. Closed-loop deep brain stimulation (DBS) paradigms that specifically target these pathological bursts of activity hold promises to help trim, and thus normalize, their abnormal behavior in real-time. Here, we developed classification algorithms that predict pathological beta bursts based on ongoing changes in LFP frequency dynamics. We then compared simulations of prediction-based DBS profiles with existing 'adaptive DBS' alternatives. We show that model-driven stimulation profiles are more precise in restricting the delivery of stimulation to bursts that are considered pathological, while preserving physiological ones. The overall stimulation time required is also diminished, thus supporting longer battery life. These results represent a conceptual and algorithmic framework for the development of more precise DBS strategies that are selectively tailored to the electrophysiological profile of each patient.