Population and Energy Transfer Dynamics in an Open Excitonic Quantum Battery.

In a previous study, we proposed an open quantum network model of a quantum battery (QB) that possesses dark states owing to its structural exchange symmetries. While in a dark state, the QB is capable of storing an exciton without any environment-induced population losses. However, when the structural exchange symmetry is broken, the QB begins to discharge the exciton towards its exit site. In this article, we start by demonstrating that this QB is not only loss-free with respect to exciton population during the storage phase, but also with respect to the QB energy. We then explore the exciton population and energy transfer dynamics of the QB during the discharge phase over a wide range of site energies, bath temperatures, and bath reorganization energies. Our results shed light on how to optimize the QB's population and energy transfer dynamics for different purposes.

Surgical prophylaxis in pediatric orthopedic patients with penicillin allergy: a multicentered retrospective prognostic study.

Up to 20% of orthopedic surgeons still avoid the use of cephalosporins in patients with penicillin allergies despite its reported safety in the adult and general surgery pediatric population. The primary objective is to determine the incidence of adverse effects and allergic reactions when using cephalosporins in pediatric orthopedic patients labeled as penicillin-allergic as compared to those without previously reported penicillin allergy. A multicenter retrospective chart review was performed across three level 1 trauma centers from January 2013 to February 2020 to identify penicillin-allergic as well as non-penicillin-allergic pediatric patients treated for orthopedic injuries. Data were collected regarding patient demographics, antibiotic administered, timing of antibiotic administration, reported drug allergy, and described allergic reaction. Postoperative or intraoperative allergic reactions to antibiotics, surgical site infections, and complications were recorded. A total of 2289 surgeries performed by four fellowship-trained surgeons were evaluated. Eighty-five patients diagnosed with penicillin allergy were identified and underwent 95 surgeries and 95 patients without previously reported penicillin allergy underwent 95 surgeries. One patient, with a documented history of anaphylaxis to cefazolin, sustained an anaphylactic reaction intraoperatively to cefazolin. There were no other reported reactions, surgical site infections, or complications. There was no statistically significant difference in rate of allergic reaction in patients with previously reported penicillin allergy treated with cefazolin and those with no previous reported reaction (P > 0.05). Prophylaxis with cephalosporins is not associated with increased risk for allergic reaction. Cephalosporins can be safely administered to pediatric patients with penicillin allergy undergoing orthopedic intervention. Level of evidence: Level II, Multicenter Retrospective Prognostic Study.

Comparing severe COVID-19 outcomes of first and second/third waves: a prospective single-centre cohort study of health-related quality of life and pulmonary outcomes 6 months after infection.

OBJECTIVE: We aimed to compare long-term outcomes in intensive care unit (ICU) survivors between the first and second/third waves of the COVID-19 pandemic. More specifically, to assess health-related quality of life (HRQL) and respiratory health 6 months post-ICU and to study potential associations between patient characteristic and treatment variables regarding 6-month outcomes. DESIGN: Prospective cohort study. SETTING: Single-centre study of adult COVID-19 patients with respiratory distress admitted to two Swedish ICUs during the first wave (1 March 2020-1 September 2020) and second/third waves (2 September 2020- 1 August 2021) with follow-up approximately 6 months after ICU discharge. PARTICIPANTS: Critically ill COVID-19 patients who survived for at least 90 days. MAIN OUTCOME MEASURES: HRQL, extent of residual changes on chest CT scan and pulmonary function were compared between the waves. General linear regression and multivariable logistic regression were used to present mean score differences (MSD) and ORs with 95% CIs. RESULTS: Of the 456 (67%) critically ill COVID-19 patients who survived at least 90 days, 278 (61%) were included in the study. Six months after ICU discharge, HRQL was similar between survivors in the pandemic waves, except that the second/third wave survivors had better role physical (MSD 20.2, 95% CI 7.3 to 33.1, p<0.01) and general health (MSD 7.2, 95% CI 0.7 to 13.6, p=0.03) and less bodily pain (MSD 12.2, 95% CI 3.6 to 20.8, p<0.01), while first wave survivors had better diffusing capacity of the lungs for carbon monoxide (OR 1.9, 95% CI 1.1 to 3.5, p=0.03). CONCLUSIONS: This study indicates that even though intensive care treatment strategies have changed with time, there are few differences in long-term HRQL and respiratory health seems to remain at 6 months for patients surviving critical COVID-19 in the first and second/third waves of the pandemic.

Electric scooter sharing systems: An analysis of injury patterns associated with their introduction.

BACKGROUND: With the increasing popularity of electric scooters (ES) and the introduction of ES sharing systems in 2017, hospitals are seeing more ES-related injuries. The effects of sharing systems on traumatic injuries are lacking in the literature. We, therefore, sought to describe trends in ES injuries. METHODS: The Nationwide Inpatient Sample was queried for patients hospitalized with ES-related injuries in the United States from 2015 to 2019. Admissions due to ES were divided into two cohorts: before (≤2017) and after (>2018) the introduction of sharing systems. Patients were stratified by injuries sustained, age, gender, and race. Inpatient hospital charges and length of stay were compared. Exclusion criteria included patients older than 65 and patients with neurological disorders. Traumatic injuries were compared after adjusting for age, gender, and race in a multivariate logistic regression analysis. RESULTS: During the study period, there were 686 admissions, of which 220 remained due to exclusion criteria. There was a consistent increase in ES-related injuries over the years (r = 0.91, p = 0.017). Patients who were injured after the introduction of sharing systems were more likely to sustain facial fractures (OR, 2.63; 95%CI, 1.30-5.32; p = 0.007) after controlling for age, gender, and race. The incidence of lumbar and pelvic fractures was higher following the introduction of such systems (7.1% vs. 0%; p<0.05). CONCLUSIONS: The introduction of ES sharing systems resulted in increased incidence of facial, pelvic, and lumbar fractures. Federal and state regulations need to be implemented to mitigate the detrimental effects of ES sharing systems.

Robotic assistance in lumbar fusion surgery: trends and patterns from 2016-2019.

PURPOSE: Robotic-assisted spine surgery is an emerging field that is growing in utilization. Intraoperative robotic surgical units cost upwards of $600,000 for medical facilities to purchase. Despite significant cost barriers, these devices are highly marketable for hospitals and physicians. METHODS: The Nationwide Inpatient Sample database from 2016 to 2019 was reviewed. Inclusion criteria were patients over 18 years of age who underwent elective lumbar spinal fusion. Trends of robotic-assisted lumbar fusion were examined over time, as well as stratified based on patient and surgical characteristics. RESULTS: A total of 176,377 patients met the inclusion criteria. The overall rate of robotic-assisted lumbar fusion was 1.2% (2,131/174,246). Patients with private insurance were more likely to receive robotic-assisted lumbar fusion (40.3% vs. 37.5%; p < 0.05). Stratifying by race, whites were more likely to receive robotic-assisted lumbar fusion (84.1% vs. 79.5%; p < 0.05). Patients who underwent robotic-assisted lumbar fusion were significantly more likely to have a diagnosis of spondylolisthesis compared to those that underwent non-robotic-assisted lumbar fusion (25.9% vs. 22.0%; p < 0.05). Patients with lumbar fusion done via the anterior approach were more likely to have robotic-assisted surgery compared to other approaches (25.2% vs. 21.3; p < 0.05). Overall, there was a steady increase in its use over time, with patients who underwent lumbar fusion procedures four times more likely to receive robotic assistance in 2019 compared to 2016 (OR: 4.0; 95% CI: 3.5-4.6; p < 0.0001). Robotic-assisted lumbar fusion was associated with higher inpatient costs ($170,036.40 vs. $139,026.10; p < 0.0001) despite having equivalent length of stay (3.31 ± 2.6 vs.3.37 ± 2.6; p = 0.06). CONCLUSION: Robotic-assisted lumbar fusion is on the rise. Patients who had private insurance, were diagnosed with spondylolisthesis, and who had lumbar fusion via the anterior approach were more likely to undergo lumbar fusion using robotic assistance.

The use of virtual interviews and new trends in orthopedic surgery residency match.

This retrospective cross-sectional study sought to determine if there was a change in geographical trends in the orthopedic surgery residency match with the use of virtual interviews. Due to the COVID-19 pandemic, visiting rotations at outside institutions were restricted and all residency interviews were conducted virtually for the 2021 match. Given these restrictions, it was hypothesized that applicants would match at a higher rate to their medical school-affiliated residency programs, or geographically nearby their medical school. Data was collected from residency program website and social media accounts to determine if the use of virtual interviews correlated with a decreased rate of matching at outside institutions. During the 2021 match, applicants who applied to orthopedic surgery in 2021 were more likely to match at their medical school-affiliated institution (OR, 1.46; 95% CI, 1.18-1.80; p < 0.01) compared to applicants during previous years. However, match rates were not different in terms of geographical regions. Virtual interviews are more cost-effective for both applicants and programs, however, this study demonstrates there are associated changes with this new interview structure. The utility of virtual interviews as a standard method in the future should take this change in trend into consideration.

Tuning Structural and Optical Properties of Porphyrin-based Hydrogen-Bonded Organic Frameworks by Metal Insertion.

Herein, a simple way of tuning the optical and structural properties of porphyrin-based hydrogen-bonded organic frameworks (HOFs) is reported. By inserting transition metal ions into the porphyrin cores of GTUB-5 (p-H8 -TPPA (5,10,15,20-Tetrakis[p-phenylphosphonic acid] HOF), the authors show that it is possible to generate HOFs with different band gaps, photoluminescence (PL) life times, and textural properties. The band gaps of the resulting HOFs (viz., Cu-, Ni-, Pd-, and Zn-GTUB-5) are measured by diffuse reflectance and PL spectroscopy, as well as calculated via DFT, and the PL lifetimes are measured. Across the series, the band gaps vary over a narrow range from 1.37 to 1.62 eV, while the PL lifetimes vary over a wide range from 2.3 to 83 ns. These differences ultimately arise from metal-induced structural changes, viz., changes in the metal-to-nitrogen distances, number of hydrogen bonds, and pore volumes. DFT reveals that the band gaps of Cu-, Zn-, and Pd- GTUB-5 are governed by highest occupied/lowest unoccupied crystal orbitals (HOCO/LUCO) composed of π- orbitals on the porphyrin linkers, while that of Ni-GTUB-5 is governed by a HOCO and LUCO composed of Ni dorbitals. Overall, our findings show that metal-insertion can be used to optimize HOFs for optoelectronics and small-molecule capture applications.

Cerebrospinal fluid (CSF) leak after elective lumbar spinal fusion: Who is at risk?

PURPOSE: CSF leaks are a known complication of lumbar fusion surgery. There is a scarcity of literature describing the incidence and risk factors associated with this complication. The aim of this study was to identify patients who are at risk of developing postoperative CSF leak. METHODS: The Nationwide Inpatient Sample database was used to identify patients who had lumbar fusion in the US from 2002 to 2014. Inpatient outcomes included the incidence and risk of developing CSF leak based on selected patient-specific characteristics. Secondary outcomes included average length of stay, mean costs, and mortality rates. All statistical analyses were conducted based on multivariate regression models using the SPSS software. RESULTS: A total of 439,220 patients who underwent elective lumbar fusion procedures were identified. Of these patients, 2.6% (11,636 /439,220) were found to have CSF leak. Independent important risk factors for CSF leak development included: older age (OR: 1.025; 95% CI: 1.02-1.03; p < 0.0001), posterior approach (OR: 1.71; 95% CI: 1.59-1.85; p < 0.0001) compared to anterior approach, chronic deficiency anemia (OR: 1.21; 95% CI:1.14-1.30; p < 0.0001), obesity (OR: 1.22; 95% CI: 1.15-1.30; p < 0.0001), and pulmonary circulatory disease (OR: 1.44; 95% CI: 1.18-1.75; p < 0.0001). CSF leak was associated with increased length of stay (5.39 ± 3.86 vs. 3.74 ± 2.55; p < 0.0001), hospitalization costs (120,129.0 ± 88,123.5 vs. 89,226.8 ± 65,350.3; p < 0.0001) and mortality (0.3% vs. 0.1%; p < 0.05). CONCLUSION: Spine surgeons should be aware of certain patient and procedure-specific characteristics that increase the risk of developing postoperative CSF leak after lumbar fusion in order to improve patient outcomes.

The role of ventilatory support for long-term outcomes after critical infection with COVID-19: A prospective cohort study.

OBJECTIVES: The full range of long-term health consequences in intensive care unit (ICU) survivors with COVID-19 is unclear. This study aims to investigate the role of ventilatory support for long-term pulmonary impairment in critically ill patients and further to identify risk factors for prolonged radiological recovery. METHODS: A prospective observational study from a single general hospital, including all with COVID-19 admitted to ICU between March and August 2020, investigating the association between ventilatory support and the extent of residual parenchymal changes on chest computed tomography (CT) scan and measurement of lung volumes at follow-up comparing high-flow nasal oxygen (HFNO) or non-invasive ventilation (NIV) with invasive ventilation. A semi-quantitative score (CT involvement score) based on lobar involvement and a total score for all five lobes was used to estimate residual parenchymal changes. The association was calculated with logistic regression and adjusted for age, sex, smoking, and severity of illness. RESULTS: Among the 187 eligible, 86 had a chest CT scan and 76 a pulmonary function test at the follow-up with a median time of 6 months after ICU discharge. Residual lung changes were seen in 74%. The extent of pulmonary changes was similar regardless of ventilatory support, but patients with invasive ventilation had a lower total lung capacity 84% versus 92% of predicted (p < 0.001). CONCLUSIONS: The majority of ICU-treated patients with COVID-19 had residual lung changes at 6 months of follow-up regardless of ventilator support or not, but the total lung capacity was lower in those treated with invasive ventilation.

Telemedicine for pediatric orthopedic visits: evaluating usability and satisfaction.

The purpose of this study is to evaluate usability and patient satisfaction with telemedicine in pediatric orthopedics using validated questionnaires and to identify demographic and clinical factors that may impact these ratings. All caregivers of patients who had telemedicine visits with a single fellowship-trained pediatric orthopedic surgeon between 23 March 2020 and 3 June 2020 were eligible to participate. Patient Satisfaction Questionnaire (PSQ) and the Telehealth Usability Questionnaire (TUQ) rated on a 4-point Likert scale (1 = poor, 2 = fair, 3 = good and 4 = excellent) were used. Additional information regarding the level of education, mode of transportation, technology usage, demographics, visit diagnosis and length of visit were collected. Quantitative analysis was performed. A total of 68.6% (83/121) of the visits were done via telemedicine. Around 46 surveys were completed with a response rate of 55.4% (46/83). The PSQ mean score was 3.63 ± 0.39 with non-English-speaking caregivers scoring lower compared to their English-speaking counterparts (3.4 ± 0.47 vs. 3.72 ± 0.33; P = 0.017). PSQ mean score increased with increasing length of visit (r = 0.352; P = 0.018). A total of 86.8% (839/966) of all TUQ's responses were good to excellent with 89.1% (41/46) of responders were satisfied with telemedicine and 91.3% (42/46) would use it again. Although the topic is an evolving one, and a lot of changes should be expected in the future, certain characteristics such as primary language and length of visit may affect the levels of satisfaction with the use of telemedicine in pediatric orthopedics. Knowledge regarding satisfaction ratings may allow orthopedic surgeons to improve patient care delivered through this technology. Level of Evidence: IV.

Coordination-Induced Band Gap Reduction in a Metal-Organic Framework.

Herein, we report on the synthesis of a microporous, three-dimensional phosphonate metal-organic framework (MOF) with the composition Cu3 (H5 -MTPPA)2 ⋅ 2 NMP (H8 -MTPPA=methane tetra-p-phenylphosphonic acid and NMP=N-methyl-2-pyrrolidone). This MOF, termed TUB1, has a unique one-dimensional inorganic building unit composed of square planar and distorted trigonal bipyramidal copper atoms. It possesses a (calculated) BET surface area of 766.2 m2 /g after removal of the solvents from the voids. The Tauc plot for TUB1 yields indirect and direct band gaps of 2.4 eV and 2.7 eV, respectively. DFT calculations reveal the existence of two spin-dependent gaps of 2.60 eV and 0.48 eV for the alpha and beta spins, respectively, with the lowest unoccupied crystal orbital for both gaps predominantly residing on the square planar copper atoms. The projected density of states suggests that the presence of the square planar copper atoms reduces the overall band gap of TUB1, as the beta-gap for the trigonal bipyramidal copper atoms is 3.72 eV.

Developmental Dysplasia of the Hip: How Does Social Media Influence Patients and Caregivers Seeking Information?

Developmental dysplasia of the hip (DDH) is a common orthopaedic condition affecting newborns. The rapid and vast adoption of social media has changed how we access medical information. The aim of this study was to deepen the understanding of the impact of social media as a tool used by caregivers. A search was performed on the Facebook (FB), Twitter (TW), and YouTube (YT) platforms. Information was quantitatively assessed by category, and number of posts and users. Comments and posts from the social medial platforms were then qualitatively assessed by using a thematic analysis. 16 Facebook pages and groups, 135 YouTube videos, and 5 Twitter accounts related to DDH were identified across 15 countries. A total of 25,471 comments/tweets were recorded. Across the social media platforms, the most common comments theme was "information sharing" (36.1%). Facebook groups had a significantly greater number of comments that were characterized as "social media as a second opinion" in comparison to YouTube videos (p < 0.001), whereas YouTube videos had significantly fewer comments characterized as "sharing information" in comparison to Facebook groups and Facebook pages (p < 0.0001). Orthopaedic surgeons may utilize caregiver presence on social media as an opportunity to help share accurate information and facilitate informed decision-making.

The role of social media in clubfoot: information sharing and social support.

PURPOSE: Clubfoot is the most common congenital foot deformity in children. Caregivers often seek medical information on the internet. The aim of the study was to characterize how social media is used by caregivers to access medical information. METHODS: A search was performed on Facebook, Twitter and YouTube platforms. Information was quantitatively assessed. Comments were qualitatively assessed, and the Kruskal-Wallis test was used to study thematic comment distribution. RESULTS: In total, 58 Facebook groups and pages, 109 YouTube accounts and ten Twitter accounts related to clubfoot were discovered from 2007 to 2019. Facebook groups and pages had a collective 56 123 members and 80 544 total likes, respectively. YouTube had a collective 3 280 454 views, with 54 969 total comments throughout the accounts. Comment themes most commonly included sharing information and advice (38.7%), appreciation and success stories (12.8%), emotional support (12.7%) and social media as a second opinion (11.9%). Facebook groups contained a significantly higher number of comments related to 'social media as a second opinion' compared with Facebook pages (p = 0.001), Twitter (p = 0.016) and YouTube (p < 0.0001) while YouTube contained a significantly lower number of comments related to 'sharing information' compared with Facebook groups, pages and Twitter (p < 0.0001). CONCLUSION: Social media continues to be a growing tool for information sharing and the findings of this study highlight the importance placed by caregivers on the advice of their peers. The online presence of caregivers may represent an opportunity for orthopaedic surgeons to communicate with patients and help them make informed decisions. LEVEL OF EVIDENCE: IV.

Quantum bath effects on nonequilibrium heat transport in model molecular junctions.

Quantum-classical dynamics simulations enable the study of nonequilibrium heat transport in realistic models of molecules coupled to thermal baths. In these simulations, the initial conditions of the bath degrees of freedom are typically sampled from classical distributions. Herein, we investigate the effects of sampling the initial conditions of the thermal baths from quantum and classical distributions on the steady-state heat current in the nonequilibrium spin-boson model-a prototypical model of a single-molecule junction-in different parameter regimes. For a broad range of parameter regimes considered, we find that the steady-state heat currents are ∼1.3-4.5 times larger with the classical bath sampling than with the quantum bath sampling. Using both types of sampling, the steady-state heat currents exhibit turnovers as a function of the bath reorganization energy, with sharper turnovers in the classical case than in the quantum case and different temperature dependencies of the turnover maxima. As the temperature gap between the hot and cold baths increases, we observe an increasing difference in the steady-state heat currents obtained with the classical and quantum bath sampling. In general, as the bath temperatures are increased, the differences between the results of the classical and quantum bath sampling decrease but remain non-negligible at the high bath temperatures. The differences are attributed to the more pronounced temperature dependence of the classical distribution compared to the quantum one. Moreover, we find that the steady-state fluctuation theorem only holds for this model in the Markovian regime when quantum bath sampling is used. Altogether, our results highlight the importance of quantum bath sampling in quantum-classical dynamics simulations of quantum heat transport.

Semiconductive microporous hydrogen-bonded organophosphonic acid frameworks.

Herein, we report a semiconductive, proton-conductive, microporous hydrogen-bonded organic framework (HOF) derived from phenylphosphonic acid and 5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin (GTUB5). The structure of GTUB5 was characterized using single crystal X-ray diffraction. A narrow band gap of 1.56 eV was extracted from a UV-Vis spectrum of pure GTUB5 crystals, in excellent agreement with the 1.65 eV band gap obtained from DFT calculations. The same band gap was also measured for GTUB5 in DMSO. The proton conductivity of GTUB5 was measured to be 3.00 × 10-6 S cm-1 at 75 °C and 75% relative humidity. The surface area was estimated to be 422 m2 g-1 from grand canonical Monte Carlo simulations. XRD showed that GTUB5 is thermally stable under relative humidities of up to 90% at 90 °C. These findings pave the way for a new family of organic, microporous, and semiconducting materials with high surface areas and high thermal stabilities.

A Nanotubular Metal-Organic Framework with a Narrow Bandgap from Extended Conjugation*.

A one-dimensional nanotubular metal-organic framework (MOF) [Ni(Cu-H4 TPPA)]⋅2 (CH3 )2 NH2 + (H8 TPPA=5,10,15,20-tetrakis[p-phenylphosphonic acid] porphyrin) constructed by using the arylphosphonic acid H8 TPPA is reported. The structure of this MOF, known as GTUB-4, was solved by using single-crystal X-ray diffraction and its geometric accessible surface area was calculated to be 1102 m2 g-1 , making it the phosphonate MOF with the highest reported surface area. Due to the extended conjugation of its porphyrin core, GTUB-4 possesses narrow indirect and direct bandgaps (1.9 eV and 2.16 eV, respectively) in the semiconductor regime. Thermogravimetric analysis suggests that GTUB-4 is thermally stable up to 400 °C. Owing to its high surface area, low bandgap, and high thermal stability, GTUB-4 could find applications as electrodes in supercapacitors.

Phosphonate Metal-Organic Frameworks: A Novel Family of Semiconductors.

Herein, the first semiconducting and magnetic phosphonate metal-organic framework (MOF), TUB75, is reported, which contains a 1D inorganic building unit composed of a zigzag chain of corner-sharing copper dimers. The solid-state UV-vis spectrum of TUB75 reveals the existence of a narrow bandgap of 1.4 eV, which agrees well with the density functional theory (DFT)-calculated bandgap of 1.77 eV. Single-crystal conductivity measurements for different orientations of the individual crystals yield a range of conductances from 10-3 to 103 S m-1 at room temperature, pointing to the directional nature of the electrical conductivity in TUB75. Magnetization measurements show that TUB75 is composed of antiferromagnetically coupled copper dimer chains. Due to their rich structural chemistry and exceptionally high thermal/chemical stabilities, phosphonate MOFs like TUB75 may open new vistas in engineerable electrodes for supercapacitors.

Nonequilibrium heat transport in a molecular junction: A mixed quantum-classical approach.

In a recent study [J. Liu et al., J. Chem. Phys. 149, 224104 (2018)], we developed a general mixed quantum-classical framework for studying heat transport through molecular junctions, in which the junction molecule is treated quantum mechanically and the thermal reservoirs to which the molecule is coupled are treated classically. This framework yields expressions for the transferred heat and steady-state heat current, which could be calculated using a variety of mixed quantum-classical dynamics methods. In this work, we use the recently developed "Deterministic Evolution of Coordinates with Initial Decoupled Equations" (DECIDE) method for calculating the steady-state heat current in the nonequilibrium spin-boson model in a variety of parameter regimes. Our results are compared and contrasted with those obtained using the numerically exact multilayer multiconfiguration time-dependent Hartree approach, and using approximate methods, including mean field theory, Redfield theory, and adiabatic mixed quantum-classical dynamics. Despite some quantitative differences, the DECIDE method performs quite well, is capable of capturing the expected trends in the steady-state heat current, and, overall, outperforms the approximate methods. These results hold promise for DECIDE simulations of nonequilibrium heat transport in realistic models of nanoscale systems.

A unique gel matrix moisturizer delivers deep hydration resulting in significant clinical improvement in radiance and texture.

Introduction: As skin ages, it loses its ability to retain moisture and becomes rough and dry. This results in a clinically dull appearance with a loss of radiance, firmness, and suppleness. Symptoms can be improved with use of a moisturizer that builds and maintains skin hydration over time; however, most moisturizers that occlude the skin surface are perceived as heavy and greasy and are not consumer preferred. Methods: A unique, consumer-preferred gel matrix formula was developed by combining liquid crystal structures, which mimic skin barrier lipid assembly, with specific emulsifiers that deliver water deep into skin. Ex vivo studies were conducted to investigate the superior hydrating effects of the gel matrix formula. Confocal Raman microscopy studies assessed the spatial distribution of water in ex vivo skin after application of the gel matrix formula. To determine the effects of the gel matrix formula on dry facial skin, a 12-week clinical study was conducted with subjects with self-perceived skin dryness and dullness. Results: The formulation significantly increased the relative water content throughout epidermal regions, which was not observed with the application of a competitive gel formula. Instrumental measurements assessed improvements in skin surface moisturization and barrier function. Clinical grading showed significant improvements in hydration-related endpoints including radiance, clarity, and texture. Subject self-agree assessment demonstrated that subjects observed improvements in the appearance of their facial skin. Conclusion: These studies demonstrated that the gel matrix formula increased skin water content in deeper layers, and resulted in significant clinical improvements in hydration, barrier function, and clinical appearance of radiance.

Heat transfer statistics in mixed quantum-classical systems.

The modelling of quantum heat transfer processes at the nanoscale is crucial for the development of energy harvesting and molecular electronic devices. Herein, we adopt a mixed quantum-classical description of a device, in which the open subsystem of interest is treated quantum mechanically and the surrounding heat baths are treated in a classical-like fashion. By introducing such a mixed quantum-classical description of the composite system, one is able to study the heat transfer between the subsystem and bath from a closed system point of view, thereby avoiding simplifying assumptions related to the bath time scale and subsystem-bath coupling strength. In particular, we adopt the full counting statistics approach to derive a general expression for the moment generating function of heat in systems whose dynamics are described by the quantum-classical Liouville equation (QCLE). From this expression, one can deduce expressions for the dynamics of the average heat and heat current, which may be evaluated using numerical simulations. Due to the approximate nature of the QCLE, we also find that the steady state fluctuation symmetry holds up to order ℏ for systems whose subsystem-bath couplings and baths go beyond bilinear and harmonic, respectively. To demonstrate the approach, we consider the nonequilibrium spin boson model and simulate its time-dependent average heat and heat current under various conditions.