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Aspergillosis of the central nervous system (CNS) is a rare condition with exceedingly high mortality. This study describes the case of an immunocompetent 42-year-old man with a history of intravenous drug use and hepatitis C who developed multiple Aspergillus lesions in the cerebellum. Despite neurosurgery and antifungal therapy with amphotericin B, he had a protracted hospital course with multiple complications, eventually developing cognitive and motor impairment due to progressive cerebellar lesions. After transfer to hospice and palliative care service, oral itraconazole was escalated to 1600 mg/day with the hope of palliating headache, nausea, and cognitive impairment. Remarkably, the patient stabilized and improved over time. After 14 months, this unprecedented high-dose regimen was discontinued, and the patient was discharged home with only mild cerebellar motor impairment. [ABSTRACT FROM AUTHOR]

Introduction: Early identification of children at risk for PTSD is critical for improving mental health outcomes after traumatic injury. Currently, there is no standard PTSD screen for pediatric trauma patients and limited data on long-term quality of life for those who screen positive., Methods: In 2022, we piloted a comprehensive routine screening program for ASD and PTSD at our Level I PTC. All admitted trauma patients ≥8 years old were eligible for screening. Inpatients were administered the ASC3. Those who screened positive were referred for follow-up and repeat mental health evaluation. PTSD screening (CTSQ, CPSS) and quality-of-life screening (PedsQL™) surveys were administered to eligible discharged trauma patients at 1-month post-injury. Children who screened positive on the CTSQ or CPSS were referred for behavioral health services., Results: 205 children were screened for ASD using the ASC3. 49/205 children (23.9 %) had a positive screen (score ≥3). 56 children completed PTSD screening at 1-month post-discharge. 14/54 children (25.9 %) screened positive on CTSQ, and 8/50 children (16 %) screened positive on CPSS. There was a significant positive correlation between CTSQ and CPSS scores (r 0.76, ∗P<0.0001). When stratified by screening results, patients who screened positive on CTSQ and CPSS were found to have the most significant correlations with poor School and Emotional Functioning on their quality-of-life inventory., Conclusion: Early screening for ASD may be predictive of later development of PTSD in children. Screening using previously validated tools (ASC3, CTSQ, CPSS) were effective in identifying children with negative emotional functioning lasting beyond the acute phase of physical recovery following injury. CTSQ and CPSS both performed well for screening at one-month post-discharge. Early identification can facilitate timely referral to mental health services to potentially minimize long-term socioemotional impact of PTSD., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Clinical clearance of a child's cervical spine after trauma is often challenging because of impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the criterion standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence magnetic resonance imaging (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared with criterion standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury., Methods: We conducted a 10-center, 5-year retrospective cohort study (2017-2021) of all children (0-18 years) with a cervical spine MRI after blunt trauma. Magnetic resonance imaging images were rereviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site., Results: We identified 2,663 children younger than 18 years who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (younger than 5 years) were more likely to be electively intubated or sedated for cervical spine MRI., Conclusion: Limited-sequence magnetic resonance imaging is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic examination., Level of Evidence: Diagnostic Test/Criteria; Level III., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background: In the pediatric population, virtual reality (VR) has been used as an adjunct to augment analgesia and reduce the need for opioids. In this study, we review our experience using VR in lieu of anesthesia or sedation to enable minor procedures in children., Methods: A retrospective chart review study was performed on patients who presented to our institution from 2019 to 2022 for hormone implant placement, exchange, or removal with VR distraction. Demographic and procedure information was recorded. The primary outcome was successful procedure completion without requiring pharmacologic sedation or analgesia., Results: A total of 111 patients underwent the following minor procedures with VR and without anesthesia or sedation. Fourteen patients had multiple encounters resulting in a total of 126 encounters. The median age was 11 [6] years. 43 patients were female, 23 were female to male, 6 were non-binary, 7 were male, and 32 were male to female. 58 % had private insurance. Most common diagnosis was precocious puberty (54 %) followed by gender dysphoria (46 %). Most common procedure was implant placement (72 %). 69 % of procedures were performed in the clinic and 31 % in the OR. All procedures were completed without requiring the administration of additional sedation or anesthesia. None of the patients required intravenous catheter placement for the procedure. No intra-procedural complications were recorded., Conclusion: VR is a feasible option that can spare children from sedation or general anesthesia for minor procedures. VR may enable minor procedures in children to be successfully performed in clinic setting., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Outcomes of pediatric patients who received extracorporeal life support (ECLS) for COVID-19 remain poorly described. The aim of this multi-institutional retrospective observational study was to evaluate these outcomes and assess for prognostic factors associated with in-hospital mortality. Seventy-nine patients at 14 pediatric centers across the United States who received ECLS support for COVID-19 infections between January 2020 and July 2022 were included for analysis. Data were extracted from the electronic medical record. The median age was 14.5 years (interquartile range [IQR]: 2-17 years). Most patients were female (54.4%) and had at least one pre-existing comorbidity (84.8%), such as obesity (44.3%, median body mass index percentile: 97% [IQR: 67.5-99.0%]). Venovenous (VV) ECLS was initiated in 50.6% of patients. Median duration of ECLS was 12 days (IQR: 6.0-22.5 days) with a mean duration from admission to ECLS initiation of 5.2 ± 6.3 days. Survival to hospital discharge was 54.4%. Neurological deficits were reported in 16.3% of survivors. Nonsurvivors were of older age (13.3 ± 6.2 years vs. 9.3 ± 7.7 years, p  = 0.012), more likely to receive renal replacement therapy (63.9% vs. 30.2%, p  = 0.003), demonstrated longer durations from admission to ECLS initiation (7.0 ± 8.1 days vs. 3.7 ± 3.8 days, p  = 0.030), and had higher rates of ECLS-related complications (91.7% vs. 69.8%, p  = 0.016) than survivors. Pediatric patients with COVID-19 who received ECLS demonstrated substantial morbidity and further investigation is warranted to optimize management strategies., Competing Interests: Disclosure: The authors have no funding and conflicts of interest to report., (Copyright © ASAIO 2023.)

Accurate energy data from noncovalent interactions are essential for constructing force fields for molecular dynamics simulations of bio-macromolecular systems. There are two important practical issues in the construction of a reliable force field with the hope of balancing the desired chemical accuracy and working efficiency. One is to determine a suitable quantum chemistry level of theory for calculating interaction energies. The other is to use a suitable continuous energy function to model the quantum chemical energy data. For the first issue, we have recently calculated the intermolecular interaction energies using the SAPT0 level of theory, and we have systematically organized these energies into the ab initio SOFG-31 (homodimer) and SOFG-31-heterodimer datasets. In this work, we re-calculate these interaction energies by using the more advanced SAPT2 level of theory with a wider series of basis sets. Our purpose is to determine the SAPT level of theory proper for interaction energies with respect to the CCSD(T)/CBS benchmark chemical accuracy. Next, to utilize these energy datasets, we employ one of the well-developed machine learning techniques, called the CLIFF scheme, to construct a general-purpose force field for biomolecular dynamics simulations. Here we use the SOFG-31 dataset and the SOFG-31-heterodimer dataset as the training and test sets, respectively. Our results demonstrate that using the CLIFF scheme can reproduce a diverse range of dimeric interaction energy patterns with only a small training set. The overall errors for each SAPT energy component, as well as the SAPT total energy, are all well below the desired chemical accuracy of ~1 kcal/mol.

A year ago, 17-year-old "Alex" was brought into the emergency department after a self-inflicted gunshot wound. Neither his primary care doctor nor his psychologist were aware of his first attempt 6 months previously. Unfortunately, this attempt was successful. It occurred in front of his home, and in front of his mother who was just seconds too late to stop him. In the aftermath, we wondered why the medical system that he had access to could not intervene in time., (Copyright © 2024 by the American Academy of Pediatrics.)

Accurate determination of intermolecular non-covalent-bonded or non-bonded interactions is the key to potentially useful molecular dynamics simulations of polymer systems. However, it is challenging to balance both the accuracy and computational cost in force field modelling. One of the main difficulties is properly representing the calculated energy data as a continuous force function. In this paper, we employ well-developed machine learning techniques to construct a general purpose intermolecular non-bonded interaction force field for organic polymers. The original ab initio dataset SOFG-31 was calculated by us and has been well documented, and here we use it as our training set. The CLIFF kernel type machine learning scheme is used for predicting the interaction energies of heterodimers selected from the SOFG-31 dataset. Our test results show that the overall errors are well below the chemical accuracy of about 1 kcal/mol, thus demonstrating the promising feasibility of machine learning techniques in force field modelling.

Background: Child abuse is a significant cause of injury and death among children, but accurate identification is often challenging. This study aims to assess whether racial disparities exist in the identification of child abuse., Methods: The 2010-2014 and 2016-2017 National Trauma Data Bank was queried for trauma patients ages 1-17. Using ICD-9CM and ICD-10CM codes, children with injuries consistent with child abuse were identified and analyzed by race., Results: Between 2010-2014 and 2016-2017, 798,353 patients were included in NTDB. Suspected child abuse victims (SCA) accounted for 7903 (1%) patients. Of these, 51% were White, 33% Black, 1% Asian, 0.3% Native Hawaiian/Other Pacific Islander, 2% American Indian, and 12% other race. Black patients were disproportionately overrepresented, composing 12% of the US population, but 33% of SCA patients (p < 0.001). Although White SCA patients were more severely injured (ISS 16-24: 20% vs 16%, p < 0.01) and had higher in-hospital mortality (9% vs. 6%, p = 0.01), Black SCA patients were hospitalized longer (7.2 ± 31.4 vs. 6.2 ± 9.9 days, p < 0.01) despite controlling for ISS (1-15: 4. 5.7 ± 35.7 vs. 4.2 ± 6.2 days, p < 0.01). In multivariate regression, Black children continued to have longer lengths of stay despite controlling for ISS and insurance type., Conclusions: Utilizing a nationally representative dataset, Black children were disproportionately identified as potential victims of abuse. They were also subjected to longer hospitalizations, despite milder injuries. Further studies are needed to better understand the etiology of the observed trends and whether they reflect potential underlying unconscious or conscious biases of mandated reporters., Type of Study: Treatment study., Level of Evidence: III., Competing Interests: Declarations of Competing Interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: In attempts to quell the spread of COVID-19, shelter-in-place orders were employed in most states. Increased time at home, in combination with parents potentially balancing childcare and work-from-home duties, may have had unintended consequences on pediatric falls from windows. We aimed to investigate rates of falls from windows among children during the first 6 mo of the COVID-19 pandemic., Methods: Patients <18 y old admitted to three pediatric trauma centers (two - level 1, one - level 2) between 3/19/20 and 9/19/20 (COVID-era) were compared to a pre-COVID cohort (3/19/19 to 9/19/19). The primary outcome was the rate of falls from windows. Secondary outcomes included injury severity score (ISS), injuries sustained, and mortality., Results: Of 1011 total COVID-era pediatric trauma patients, 36 (3.6%) sustained falls from windows compared to 23 of 1108 (2.1%) pre-COVID era patients (OR 1.7, P = 0.05). The median ISS was seven pre-COVID versus four COVID-era (P = 0.43). The most common injuries sustained were skull fractures (30.5%), extremity injuries (30.5%), and intracranial hemorrhage (23.7%). One-fifth of patients underwent surgery (21.7% pre-COVID versus 19.4% COVID-era, P = 1.0). There was one mortality in the COVID-era cohort and none in the pre-COVID cohort (P = 1.0)., Conclusions: Despite overall fewer trauma admissions during the first 6 mo of the COVID-19 pandemic, the rate of falls from windows nearly doubled compared to the prior year, with substantial associated morbidity. These findings suggest a potential unintended consequence of shelter-in-place orders and support increased education on home safety and increased support for parents potentially juggling multiple responsibilities in the home., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

We extend our previous quantum chemistry calculations of interaction energies for 31 homodimers of small organic functional groups (the SOFG-31 data set) by including 239 heterodimers with monomers selected within the SOFG-31 data set, thus resulting in the SOFG-31+239 data set. The minimum-level theoretical scheme contains (1) the basis set superposition error corrected supermolecule (BSSE-SM) approach for intermolecular interactions; (2) the second-order Møller-Plesset perturbation theory (MP2) with the Dunning's aug-cc-pVXZ (X = D, T, Q) basis sets for the geometry optimization and correlation energy calculations; and (3) the single-point energy calculations with the coupled cluster with single, double, and perturbative triple excitations method at the complete basis set limit [CCSD(T)/CBS] using the well-tested extrapolation methods for the MP2 energy calibrations. In addition, we have performed a parallel series of energy decomposition calculations based on the symmetry adapted perturbation theory (SAPT) in order to gain chemical insights. That the above procedure cannot be further reduced has been proven to be very crucial for constructing reliable data sets of interaction energies. The calculated CCSD(T)/CBS interaction energy data can serve as a benchmark for testing or training less accurate but more efficient calculation methods, such as the electronic density functional theory. As an application, we employ a segmental SAPT model previously developed for the SOFG-31 data set to predict binding energies of large heterodimer complexes. These model energy "quanta" can be used in coarse-grained molecular dynamics simulations by avoiding large-scale calculations., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Purpose: Ultrasound-guided transversus abdominis plane (TAP) blocks have been demonstrated to decrease postoperative pain; however, laparoscopic-assisted TAP (L-TAP) blocks have not been well studied in children. Our study utilized intraoperative ultrasound to verify whether surgeon-administered blocks using only laparoscopic visualization were reliably delivered into the correct plane. Materials and Methods: Patients undergoing laparoscopic procedures were enrolled to receive L-TAP blocks. Preblock and postblock ultrasounds were performed to document the plane of local anesthetic delivery. Ultrasound images were reviewed by two blinded anesthesiologists to determine whether the L-TAP block was administered into the desired plane. Results: Fifty-one patients were enrolled. The average age was 5.9 years (range: 2 days to 17 years) and the mean weight was 25.4 kg (range: 2.64-118.8 kg). The most common procedures were inguinal hernia repair ( n  = 19), appendectomy ( n  = 10), and gastrostomy-tube placements ( n  = 13). Nine surgeons performed 93 L-TAP blocks (average: 10.3 blocks/surgeon). Ultrasound confirmed distribution in the correct plane in 53.5/93 blocks (57.5%; 58.0% for attending surgeons), with 77.4% concurrence between the anesthesiologist reviewers. Conclusion: L-TAP achieves delivery of local anesthetic into the correct tissue plane in over half the cases with minimal training. Further studies are needed to examine the effect of L-TAP blocks on reducing postoperative pain in pediatric patients.

Background: Economic, social, and psychologic stressors are associated with an increased risk for abusive injuries in children. Prolonged physical proximity between adults and children under conditions of severe external stress, such as witnessed during the COVID-19 pandemic with "shelter-in-place orders", may be associated with additional increased risk for child physical abuse. We hypothesized that child physical abuse rates and associated severity of injury would increase during the early months of the pandemic as compared to the prior benchmark period., Methods: We conducted a nine-center retrospective review of suspected child physical abuse admissions across the Western Pediatric Surgery Research Consortium. Cases were identified for the period of April 1-June 30, 2020 (COVID-19) and compared to the identical period in 2019. We collected patient demographics, injury characteristics, and outcome data., Results: There were no significant differences in child physical abuse cases between the time periods in the consortium as a whole or at individual hospitals. There were no differences between the study periods with regard to patient characteristics, injury types or severity, resource utilization, disposition, or mortality., Conclusions: Apparent rates of new injuries related to child physical abuse did not increase early in the COVID-19 pandemic. While this may suggest that pediatric physical abuse was not impacted by pandemic restrictions and stresses, it is possible that under-reporting, under-detection, or delays in presentation of abusive injuries increased during the pandemic. Long-term follow-up of subsequent rates and severity of child abuse is needed to assess for unrecognized injuries that may have occurred., Competing Interests: Declaration of Competing Interest There are no conflicts of interest., (Copyright © 2021. Published by Elsevier Inc.)

Introduction: Traumatic injury is the leading cause of morbidity and mortality among children in the United States. Single institution studies suggest an increased risk of poor mental health outcomes among these patients, but there are few population-based studies assessing this risk., Methods: The IBM Ⓡ MarketScan Ⓡ private insurance claims database was used to identify children (6-17yo) with traumatic injuries between 2007 and 2016. Time-to-event analysis was performed to compare rates of PTSD, depression, anxiety, and adjustment disorder among children admitted to the hospital compared to children treated in the emergency department (ED), urgent care (UC), or in the outpatient setting, and to children admitted with uncomplicated appendicitis., Results: Among children admitted for traumatic injury, 3.3% developed a subsequent mental health diagnosis, and 1.6% developed PTSD. Children admitted for traumatic injury were at increased risk of developing a mental health condition (HR 1.34, p < 0.001) compared to those admitted for appendicitis. Children treated in the ED or UC for traumatic injury and those treated in the outpatient setting were also at increased risk (HR 1.20 and 1.18, p = 0.006 and p = 0.012, respectively). Among those admitted to the hospital, the risk of subsequent mental health diagnosis increased by 1.5% per day; in the first 31 days of hospitalization, the risk of PTSD diagnosis increased by 13% per day., Conclusion: Children who sustain a traumatic injury are at increased risk of developing a mental health condition. PTSD rates found in our real world analysis are lower than those found in prospective studies, raising the possibility of under-recognition of PTSD in this population., Level of Evidence: Level II., Competing Interests: Declaration of Competing Interest None to Declare., (Copyright © 2021. Published by Elsevier Inc.)

Background: Pediatric trauma patients are treated at adult trauma centers (ATCs), mixed pediatric and ATCs (MTC), or pediatric trauma centers (PTCs). Shock index, pediatric age-adjusted (SIPA) can prospectively identify severely injured children. This study characterized the differences in mortality and hospital length of stay (LOS) among pediatric trauma patients with elevated SIPA (eSIPA) at different trauma centers types., Methods: Pediatric patients (1-14 years) were queried from the 2013 to 2016 National Trauma Data Bank. Patients with eSIPA were included for analysis. The primary outcome was mortality. Secondary outcomes included rates of splenectomy, computed tomography chest scans, laparotomy, and hospital LOS. Unadjusted frequencies and multivariable regression analyses were performed. An alpha level of 0.01 was used to determine significance., Results: Out of 189,003 pediatric trauma patients, 15,832 were included for analysis. After controlling for age, race, sex, payment method, Injury Severity Score, Glasgow Coma Scale score, hospital teaching status, and number of hospital beds, there was no significant difference in mortality among eSIPA patients at ATCs (odds ratio [OR], 0.753; p = 0.078) and MTCs (OR, 1.051; p = 0.776) when compared with PTCs. This remained true even among the most severely injured eSIPA patients (Injury Severity Score > 25). Splenectomy rates were higher at ATCs (OR, 3.234; p = 0.005), as were computed tomography chest scan rates (ATC OR, 4.423; p < 0.001; MTC OR, 6.070; p < 0.001) than at PTCs. There was a trend toward higher splenectomy rates at MTCs (OR, 2.910; p = 0.030) compared with PTCs, but this did not reach statistical significance. Laparotomy rates and hospital LOS were not significantly different., Conclusion: Among eSIPA pediatric trauma patients, there was no difference in mortality between trauma center types. However, other secondary findings indicate that specialty care at PTCs may help optimize the care of pediatric trauma patients., Level of Evidence: Retrospective cohort study, level IV., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: Children often require anesthesia for simple diagnostic and therapeutic procedures. The aim of this study was to evaluate the feasibility of using virtual reality (VR) to reduce sedation in children undergoing minor surgical procedures., Method: In this prospective, non-randomized clinical trial, pediatric patients at a free-standing children's hospital undergoing hormone implant placement, removal, or exchange were recruited to use VR and local anesthesia instead of procedural sedation or general anesthesia (GA). Patients were enrolled between November 2017 and March 2020, and were compared to historic controls who underwent similar procedures without VR between April 2016 and February 2020. Primary outcome measure was successful procedure completion without sedation or GA. Secondary measures included assessments of pain, fear and anxiety, patient compliance, procedural and recovery times., Results: Twenty-eight patients underwent 29 procedures with VR. Hormone implants (72%), removals (7%), or exchanges (21%) were completed without GA, sedation or IV placement. Procedure lengths and pain scores were similar between VR patients and historic controls, but recovery times were significantly shorter in VR patients (18 vs 65 min, p < 0.001). Participant satisfaction scores were high, with 95% recommending VR to others., Conclusions: VR is a feasible alternative to sedation or GA for select pediatric patients undergoing minor surgical procedures., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: The first COVID-19 cases occurred in the US in January of 2020, leading to the implementation of shelter in place. This study seeks to define the impact of shelter in place on the epidemiology of pediatric trauma., Methods: We examined pediatric trauma admissions at 5 Level 1 and 1 Level 2 US pediatric trauma centers between January 1 and June 30, 2017-2020. Demographic and injury data were compared between pre- and post-shelter in place patient cohorts., Results: A total of 8772 pediatric trauma activations were reviewed. There was a 13% decrease in trauma volume in 2020, with a nadir at 16 days following implementation of shelter in place. Injury severity scores were higher in the post-shelter in place cohort. The incidence of nonmotorized vehicle accidents and gunshot wounds increased in the post-shelter in place cohort., Conclusion: We found an overall decrease in pediatric trauma volume following shelter in place. However, injuries tended to be more severe. Our findings help inform targeted injury prevention campaigns during future pandemics., (© 2021 The Authors.)

We have performed a quantum chemistry study on the bonding patterns and interaction energies for 31 dimers of small organic functional groups (dubbed the SOFG-31 dataset), including the alkane-alkene-alkyne (6 + 4 + 4 = 14, AAA) groups, alcohol-aldehyde-ketone (4 + 4 + 3 = 11, AAK) groups, and carboxylic acid-amide (3 + 3 = 6, CAA) groups. The basis set superposition error corrected super-molecule approach using the second order Møller-Plesset perturbation theory (MP2) with the Dunning's aug-cc-pVXZ (X = D, T, Q) basis sets has been employed in the geometry optimization and energy calculations. To calibrate the MP2 calculated interaction energies for these dimeric complexes, we perform single-point calculations with the coupled cluster with single, double, and perturbative triple excitations method at the complete basis set limit [CCSD(T)/CBS] using the well-tested extrapolation methods. In order to gain more physical insights, we also perform a parallel series of energy decomposition calculations based on the symmetry adapted perturbation theory (SAPT). The collection of these CCSD(T)/CBS interaction energy values can serve as a minimum quantum chemistry dataset for testing or training less accurate but more efficient calculation methods. As an application, we further propose a segmental SAPT model based on chemically recognizable segments in a specific functional group. These model interactions can be used to construct coarse-grained force fields for larger molecular systems.

Background: Corrective surgery for pectus excavatum often relies on the Haller index (HI), derived from chest roentgenograms or computed tomography; however, this exposes children to potentially unnecessary radiation. Our aim was to develop a novel three-dimensional (3D) optical imaging technique to accurately measure chest wall dimensions in a clinically relevant manner., Methods: Patients with pectus excavatum were imaged using a 3D structured light scanner. Patient characteristics, including height, weight, body mass index, and radiographic HIs (rHI) were recorded. We defined the optical index (OI) as the ratio of the lateral to anterior-posterior measurements obtained from the 3D optical images and compared those to patients' rHIs. Two-thirds of the patients' images were used to develop a predictive model of the rHI, using their OI and biometric data in multilinear regression modeling. The predictive model was applied to the remaining images, and the predicted HIs (pHI) were compared to the rHIs., Results: Optical imaging was performed in 42 patients (ages, 5-35 years) with pectus excavatum; of these, 31 had recent chest roentgenograms, with rHIs ranging from 2.00 to 7.20. The OIs derived from the images correlated closely with rHIs (r = 0.850). Our predictive model, using patients' OI, height, and weight, was able to accurately estimate their rHIs with a median error of 8.11% (interquartile range, 3.5%-17.4%)., Conclusions: 3D optical imaging of patients with pectus excavatum is emerging as an alternative method to assess HIs without the use of ionizing radiation. Additional studies will focus on volumetric quantification of chest wall deformities, using the 3D capabilities of this technology., (Copyright © 2019 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Our study aims to describe how obstetricians manage pregnant women infected with chronic hepatitis B in a region with a large high-risk population., Methods: We performed a cross-sectional study among practicing obstetricians in Santa Clara County, California. All obstetricians practicing in Santa Clara County were invited to participate in the study. Obstetricians were recruited in person or by mail to complete a voluntary, multiple choice survey on hepatitis B (HBV). Survey questions assessed basic HBV knowledge and obstetricians' self-reported clinical practices of the management of HBV-infected pregnant women. Pooled descriptive analyses were calculated for the cohort, as well as, correlation coefficients to evaluate the association between reported clinical practices and hepatitis B knowledge., Results: Among 138 obstetricians who completed the survey, 94% reported routinely testing pregnant women for hepatitis B surface antigen (HBsAg) with each pregnancy. Only 60.9% routinely advised HBsAg-positive patients to seek specialist evaluation for antiviral treatment and monitoring and fewer than half (48.6%) routinely provided them with HBV information. While most respondents recognized the potential complications of chronic HBV (94.2%), only 21% were aware that chronic HBV carries a 25% risk of liver related death when left unmonitored and untreated, and only 25% were aware of the high prevalence of chronic HBV in the foreign-born Asian, Native Hawaiian and Pacific Islander population. Obstetricians aware of the high risk of perinatal HBV transmission were more likely to test pregnant women for HBV DNA or hepatitis B e-antigen in HBV-infected women (r = 0.18, p = 0.033). Obstetricians who demonstrated knowledge of the long-term consequences of untreated HBV infection were no more likely to refer HBV-infected women to specialists for care (r = 0.02, p = 0.831)., Conclusion: Our study identified clear gaps in the practice patterns of obstetricians that can be readily addressed to enhance the care they provide to HBV-infected pregnant women.

Background: Firearm-related injuries are the second leading cause of pediatric deaths in the US. We sought to evaluate the effectiveness of both state child access prevention (CAP) laws and gun regulations on pediatric firearm mortality. We hypothesized that states with more stringent firearm legislation had lower pediatric firearm mortality., Study Design: We used 2014-2015 firearm mortality data from the Web-Based Injury Statistics Query and Reporting System, 2014 Brady scores (used to quantify stringency of state gun regulations) and CAP laws. State-level covariates were obtained from government sources, including the Bureau of Labor Statistics and the Department of Education. Spearman rank correlations and linear regression were used to determine the relationship between overall pediatric firearm mortality and gun regulations. We also examined the relationship between gun regulations and firearm-related homicides and suicides., Results: Annually, there were approximately 2,715 pediatric firearm fatalities among children; 62.1% were homicides and 31.4% suicides. There was a moderate negative correlation between states' firearm legislation stringency and overall pediatric firearm mortality (ρ = -0.66; p < 0.001), and between CAP laws and firearm suicide rates (ρ = -0.56; p < 0.001). After controlling for poverty, unemployment, substance abuse, and the number of registered firearms, the association between firearm legislation stringency and overall pediatric firearm mortality remained significant (p = 0.04). The association between CAP laws and firearm suicide rate remained significant after controlling for socioeconomic factors, registered firearms, and other firearm legislation (p = 0.04)., Conclusions: Strict gun legislation and CAP laws are associated with fewer pediatric firearm fatalities and firearm suicides, respectively, though no such association was identified with pediatric firearm homicides. Although more studies are needed to determine causality, state-level legislation could play an important role in reducing pediatric firearm-related deaths., (Copyright © 2019 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Total colonic and small bowel aganglionosis (TCSA) occurs in less than 1% of all Hirschsprung's disease patients. Currently, the mainstay of treatment is surgery. However, in patients with TCSA, functional outcomes are often poor. A characteristic transition zone in TCSA can be difficult to identify which may complicate surgery and may often require multiple operations., Case Presentation: We present the case of a male infant who was diagnosed with biopsy-proven total colonic aganglionosis with extensive small bowel involvement as a neonate. The patient was diverted at one month of age based on leveling biopsies at 10 cm from the Ligament of Treitz. At 7 months of age, during stoma revision for a prolapsed stoma, intra-operative peristalsis was observed in nearly the entire length of the previously aganglionic bowel, and subsequent biopsies demonstrated the appearance of mature ganglion cells in a previously aganglionic segment., Conclusions: TCSA remains a major challenge for pediatric surgeons. Our case introduces new controversy to our understanding of aganglionosis. Our observations warrant further research into the possibility of post-natal ganglion maturation and encourage surgeons to consider a more conservative surgical approach.

Background: Legal firearm sales occur largely through suppliers that have Federal Firearm Licensees (FFLs). Since FFL density might reflect ease-of-access to firearm purchases, we hypothesized that the number of FFL dealers would be associated with firearm-related deaths. We further hypothesized that licensee-type subsets would be associated with differential risks for gun-related deaths., Methods: We used data from the National Center for Health Statistics National Vital Statistics System (2008-2014) and national data on Federal Firearms Licensees for 2014. Correlation analysis and linear regression analysis were performed to determine the relationship between different licensee types and firearm-related deaths. We controlled for population, number of statewide registered firearms, and the density of other types of FFLs., Results: We identified a total of 65,297 FFLs. There was a moderate correlation (R = 0.53, ρ = 0.48) between total FFL density and firearm-related death rates. Further analysis by type of firearm-related death showed a strong correlation (R = 0.81, ρ = 0.76) between total FFL density and firearm-related suicide rates. No correlation was found between total FFL density and firearm-related homicide rate. Among individual FFL types, FFL02 (firearm dealing pawnshop) density was the only FFL-type found to be correlated with firearm-related death rates. We found a strong correlation between FFL02 density and overall firearm-related death rate (R = 0.69, ρ = 0.78) and firearm-related suicide rate (R = 0.72, ρ = 0.78). Linear regression analysis showed that even while controlling for number of registered firearms and population, the number of firearm-dealing pawnshops remained significantly associated with overall firearm-related deaths and firearm-related suicides., Conclusion: Access to legally distributed firearms is associated with firearm-related death rates, particularly firearm-related suicides. Specifically, firearm-dealing pawnshops were associated with suicide-related deaths. These findings suggest that deeper exploration of legal firearm access and firearm-related injuries would benefit discussion of preventative measures., Level of Evidence: Therapeutic, Level V.

Background: Achalasia is a primary esophageal motility disorder characterized by aperistalsis of the esophagus and failed relaxation of the lower esophageal sphincter that presents rarely in childhood. The peroral endoscopic myotomy (POEM) procedure is an emerging treatment for achalasia in adults that has recently been introduced into pediatric surgical practice., Methods: This is a prospective case series of all children referred to Stanford University Lucile Packard Children's Hospital with manometry-confirmed achalasia who underwent a POEM procedure from 2014 to 2016., Results: We enrolled 10 subjects ranging in age from 7 to 17years (M=13.4). The mean pre- and 1-month post-procedure Eckardt scores were 7 (SD=2.5) and 2.4 (SD=2) (p<0.001), respectively. The median procedure time for the entire cohort was 142min (range 60-259min) with ongoing improvement with increased experience (R 2 =0.6, p=0.008). There were no major adverse events., Conclusion: The POEM procedure can be successfully completed in children for the treatment of achalasia with demonstrated short-term post-operative improvement in symptoms. The adoption of advanced endoscopic techniques by pediatric surgeons may enable development of unique intraluminal approaches to congenital anomalies and other childhood diseases., Level of Evidence: Treatment Study - Level IV., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This paper presents a coarse-grained molecular simulation for fullerenes based on a multipolar expansion method developed previously. The method is enabled by the construction of transferable united atoms potentials that approximate the full atomistic intermolecular interactions, as obtained from ab initio electronic structure calculations supplemented by empirical force fields and experimental data, or any combination of the above. The resultant series contains controllable moment tensors that allow to estimate the errors, and approaches the all-atom intermolecular potential as the expansion order increases. We can compute the united atoms potentials very efficiently with a few interaction moment tensors, in order to implement a parallel algorithm on molecular interactions. Our simulations describe the mechanism for the condensation of fullerenes, and they produce excellent agreement with benchmark fully atomistic molecular dynamics simulations.

Modeling fluid cycloalkanes with molecular dynamics simulations has proven to be a very challenging task partly because of lacking a reliable force field based on quantum chemistry calculations. In this paper, we construct an ab initio force field for fluid cyclopropane using the second-order Møller-Plesset perturbation theory. We consider 15 conformers of the cyclopropane dimer for the orientation sampling. Single-point energies at important geometries are calibrated by the coupled cluster with single, double, and perturbative triple excitation method. Dunning's correlation consistent basis sets (up to aug-cc-pVTZ) are used in extrapolating the interaction energies at the complete basis set limit. The force field parameters in a 9-site Lennard-Jones model are regressed by the calculated interaction energies without using empirical data. With this ab initio force field, we perform molecular dynamics simulations of fluid cyclopropane and calculate both the structural and dynamical properties. We compare the simulation results with those using an empirical force field and obtain a quantitative agreement for the detailed atom-wise radial distribution functions. The experimentally observed gross radial distribution function (extracted from the neutron scattering measurements) is well reproduced in our simulation. Moreover, the calculated self-diffusion coefficients and shear viscosities are in good agreement with the experimental data over a wide range of thermodynamic conditions. To the best of our knowledge, this is the first ab initio force field which is capable of competing with empirical force fields for simulating fluid cyclopropane.

We present the case of a 15-year-old female with a right perineal mass that was found to be pleomorphic myxoid liposarcoma, a recently recognized, rare subtype of liposarcoma. The patient had a strong family history of malignancy and genetic screening revealed a pathogenic TP53 mutation consistent with Li-Fraumeni syndrome.

We have used the recently developed kinetic energy partition (KEP) method to solve the quantum eigenvalue problems for helium-like atoms and obtain precise ground state energies and wave-functions. The key to treating properly the electron-electron (repulsive) Coulomb potential energies for the KEP method to be applied is to introduce a "negative mass" term into the partitioned kinetic energy. A Hartree-like product wave-function from the subsystem wave-functions is used to form the initial trial function, and the variational search for the optimized adiabatic parameters leads to a precise ground state energy. This new approach sheds new light on the all-important problem of solving many-electron Schrödinger equations and hopefully opens a new way to predictive quantum chemistry. The results presented here give very promising evidence that an effective one-electron model can be used to represent a many-electron system, in the spirit of density functional theory.

Aim: To investigate physicians' knowledge including chronic hepatitis B (CHB) diagnosis, screening, and management in various stages of their training., Methods: A voluntary 20-question survey was administered in Santa Clara County, CA where Asian and Pacific Islanders (API) account for a third of the population. Among the 219 physician participants, there were 63 interns, 60 second-year residents, 26 chief residents and 70 attending physicians. The survey asked questions regarding respondents' demographics, general hepatitis B virus knowledge questions (i.e., transmission, prevalence, diagnostic testing, prevention, and treatment options), as well as, self-reported practice behavior and confidence in knowledge., Results: Knowledge about screening and managing patients with CHB was poor: only 24% identified the correct tests to screen for CHB, 13% knew the next steps for patients testing positive for CHB, 18% knew the high prevalence rate among API, and 31% knew how to screen for liver cancer. Wald chi-square analysis determined the effect of training level on knowledge; in all cases except for knowledge of liver cancer screening (P = 0.0032), knowledge did not significantly increase with length in residency training or completion of residency., Conclusion: Even in a high-risk region, both medical school and residency training have not adequately prepared physicians in the screening and management of CHB.

A quartz crystal microbalance (QCM) serving as a biosensor to detect the target biomolecules (analytes) often suffers from the time consuming process, especially in the case of diffusion-limited reaction. In this experimental work, we modify the reaction chamber of a conventional QCM by integrating into the multi-microelectrodes to produce electrothermal vortex flow which can efficiently drive the analytes moving toward the sensor surface, where the analytes were captured by the immobilized ligands. The microelectrodes are placed on the top surface of the chamber opposite to the sensor, which is located on the bottom of the chamber. Besides, the height of reaction chamber is reduced to assure that the suspended analytes in the fluid can be effectively drived to the sensor surface by induced electrothermal vortex flow, and also the sample costs are saved. A series of frequency shift measurements associated with the adding mass due to the specific binding of the analytes in the fluid flow and the immobilized ligands on the QCM sensor surface are performed with or without applying electrothermal effect (ETE). The experimental results show that electrothermal vortex flow does effectively accelerate the specific binding and make the frequency shift measurement more sensible. In addition, the images of the binding surfaces of the sensors with or without applying electrothermal effect are taken through the scanning electron microscopy. By comparing the images, it also clearly indicates that ETE does raise the specific binding of the analytes and ligands and efficiently improves the performance of the QCM sensor.

We perform an ab initio computational study of molecular complexes with the general formula CF3X-B that involve one trifluorohalomethane CF3X (X = Cl or Br) and one of a series of Lewis bases B in the gas phase. The Lewis bases are so chosen that they provide a range of electron-donating abilities for comparison. Based on the characteristics of their electron pairs, we consider the Lewis bases with a single n-pair (NH3 and PH3), two n-pairs (H2O and H2S), two n-pairs with an unsaturated bond (H2CO and H2CS), and a single π-pair (C2H4) and two π-pairs (C2H2). The aim is to systematically investigate the influence of the electron pair characteristics and the central atom substitution effects on the geometries and energetics of the formed complexes. The counterpoise-corrected supermolecule MP2 and coupled-cluster single double with perturbative triple [CCSD(T)] levels of theory have been employed, together with a series of basis sets up to aug-cc-pVTZ. The angular and radial configurations, the binding energies, and the electrostatic potentials of the stable complexes have been compared and discussed as the Lewis base varies. For those complexes where halogen bonding plays a significant role, the calculated geometries and energetics are consistent with the σ-hole model. Upon formation of stable complexes, the C-X bond lengths shorten, while the C-X vibrational frequencies increase, thus rendering blueshifting halogen bonds. The central atom substitution usually enlarges the intermolecular bond distances while it reduces the net charge transfers, thus weakening the bond strengths. The analysis based on the σ-hole model is grossly reliable but requires suitable modifications incorporating the central atom substitution effects, in particular, when interaction components other than electrostatic contributions are involved.

We have calculated the intermolecular interaction energies of the chloroform dimer in 12 orientations using the second-order Møller-Plesset perturbation theory. Single point energies of important geometries were calibrated by the coupled cluster with single and double and perturbative triple excitation method. Dunning's correlation consistent basis sets up to aug-cc-pVQZ have been employed in extrapolating the interaction energies to the complete basis set limit values. With the ab initio potential data we constructed a 5-site force field model for molecular dynamics simulations. We compared the simulation results with recent experiments and obtained quantitative agreements for the detailed atomwise radial distribution functions. Our results were also consistent with previous results using empirical force fields with polarization effects. Moreover, the calculated diffusion coefficients reproduced the experimental data over a wide range of thermodynamic conditions. To the best of our knowledge, this is the first ab initio force field which is capable of competing with existing empirical force fields for liquid chloroform.

Background: This study aimed to better understand the barriers to perinatal hepatitis B prevention and to identify the reasons for poor hepatitis B knowledge and delivery of education to hepatitis B surface-antigen- positive pregnant women among healthcare providers in Santa Clara County, California., Materials and Methods: Qualitative interviews were conducted with 16 obstetricians and 17 perinatal nurses in Santa Clara County, California, which has one of the largest populations in the United States at high risk for perinatal hepatitis B transmission., Results: Most providers displayed a lack of self-efficacy attributed to insufficient hepatitis B training and education. They felt discouraged from counseling and educating their patients because of a lack of resources and discouraging patient attitudes such as stigma and apathy. Providers called for institutional changes from the government, hospitals, and nonprofit organizations to improve care for patients with chronic hepatitis B., Conclusions: Early and continuing provider training, increased public awareness, and development of comprehensive resources and new programs may contribute to reducing the barriers for health care professionals to provide counseling and education to pregnant patients with chronic hepatitis B infection.

Objective: To evaluate current levels of hepatitis-B-related knowledge and clinical practice among perinatal nurses., Design: Cross-sectional study., Setting: Santa Clara County, California, home to one of the largest U.S. populations at risk of perinatal hepatitis B transmission., Participants: Perinatal nurses (N = 518) from eight birthing hospitals., Methods: In 2008-2010, nurses completed a baseline survey evaluating existing hepatitis-B-related knowledge and preventive clinical practices, participated in an educational seminar, received instructional materials about hepatitis B, and completed a follow-up knowledge survey., Results: Eighty percent of perinatal nurses had provided health care to a pregnant woman with chronic hepatitis B, but only 51% routinely provided patients with educational information about hepatitis B. While 75% routinely informed patients about effective methods to prevent mother-to-child transmission, only a small minority (17-34%) educated infected women about standard recommendations for protecting themselves and household members. One fourth or fewer nurses correctly answered most questions about hepatitis B prevalence, risks, and symptoms. After the educational seminar, knowledge increased statistically significantly., Conclusion: Existing knowledge about hepatitis B is limited, and nationally recommended preventive clinical practices are commonly overlooked by perinatal nurses. This lack of knowledge and preventive care represents a noteworthy gap and an opportunity for targeted training and education to improve perinatal hepatitis B prevention and medical management of infected mothers., (© 2012 AWHONN, the Association of Women's Health, Obstetric and Neonatal Nurses.)

We have used molecular dynamic simulations to study the structural and dynamical properties of liquid dimethyl ether (DME) with a newly constructed ab initio force field in this article. The ab initio potential energy data were calculated at the second order Møller-Plesset (MP2) perturbation theory with Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). We considered 17 configurations of the DME dime for the orientation sampling. The calculated MP2 potential data were used to construct a 3-site united atom force field model. The simulation results are compared with those using the empirical force field of Jorgensen and Ibrahim (Jorgensen and Ibrahim, J Am Chem Soc 1981, 103, 3976) and with available experimental measurements. We obtain quantitative agreements for the atom-wise radial distribution functions, the self-diffusion coefficients, and the shear viscosities over a wide range of experimental conditions. This force field thus provides a suitable starting point to predict liquid properties of DME from first principles intermolecular interactions with no empirical data input a priori., (Copyright © 2012 Wiley Periodicals, Inc.)

Intermolecular interaction potentials of the trifluoromethane dimer in 15 orientations have been calculated using the Hartree-Fock (HF) self-consistent theory and the second-order Møller-Plesset (MP2) perturbation theory. Single point energies at important geometries were also calibrated by the coupled cluster with single and double and perturbative triple excitation [CCSD(T)] calculations. We have employed Pople's medium size basis sets [up to 6-311++G(3df,3pd)] and Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). Basis set limit potential values were obtained through well-studied extrapolation methods. The calculated MP2 potential data were employed to parameterize a 5-site force field for molecular simulations. We performed molecular dynamics simulations using the constructed ab initio force field and compared the simulation results with experiments. Quantitative agreements for the atom-wise radial distribution functions and the self-diffusion coefficients over a wide range of experimental conditions can be obtained, thus validating the ab initio force field without using experimental data a priori., (Copyright © 2011 Wiley Periodicals, Inc.)

We have calculated the structural and energetic properties of neutral and ionic (singly charged anionic and cationic) semiconductor binary silicon-germanium clusters Si(m)Ge(n) for s = m + n ≤ 12 using the density functional theory (DFT-B3LYP) and coupled cluster [CCSD(T)] methods with Pople's 6-311++G(3df, 3pd) basis set. Neutral and anionic clusters share similar ground state structures for s = 3-7, independent of the stoichiometry and atom locations, but start to deviate at s = 8. The relative energetic stability of the calculated ground state structures among possible isomers has been analyzed through a bond strength propensity model where the pair interactions of Si-Si, Si-Ge, and Ge-Ge are competing. Electron affinities, ionization potentials, energy gaps between the highest and lowest occupied molecular orbitals (HOMO-LUMO gaps), and cluster mixing energies were calculated and analyzed. Overall, for a fixed s, the vertical ionization potential increases as the number of silicon atoms m increases, while the vertical electron affinity shows a dip at m = 2. As s increases, the ionization potentials increase from s = 2 to s = 3 and then decrease slowly to s = 8. The mixing energies for neutral and ionic clusters are all negative, indicating that the binary clusters are more stable than pure elemental clusters. Except for s = 4 and 8, cationic clusters are more stable than anionic ones and, thus, are more likely to be observed in experiments.

We have theoretically studied important dynamic processes involved in zero electron kinetic energy (ZEKE) spectroscopy using the density matrix method with the inverse Born-Oppenheimer approximation basis sets. In ZEKE spectroscopy, the ZEKE Rydberg states are populated by laser excitation (either a one- or two-photon process), which is followed by autoionizations and l-mixing due to a stray field. The discrimination field is then applied to ionize loosely bound electrons in the ZEKE states. This is followed by using the extraction field to extract electrons from the ZEKE levels which have a strength comparable to that of the extraction field. These extracted electrons are measured for the relative intensities of the ion states under investigation. The spectral positions are determined by the applied laser wavelength and modified by the extraction electric field. In this paper, all of these processes are conducted within the context of the density matrix method. The density matrix method can provide not only the dynamics of system's population and coherence (or phase) but also the rate constants of the processes involved in the ZEKE spectroscopy. Numerical examples are given to demonstrate the theoretical treatments.

Intermolecular interaction potentials of the carbon tetrachloride dimer in 12 orientations have been calculated using the Hartree-Fock self-consistent theory and the second-order Moller-Plesset (MP2) perturbation theory. We have employed basis sets from Pople's medium size basis sets [up to 6-311++G(3df,3pd)] to Dunning's correlation consistent basis sets (up to aug-cc-pVQZ). The calculated MP2 potential data were employed to parametrize a four-site force field for molecular simulations. We performed molecular dynamics simulations using the ab initio force field and compared the simulation results to experiments. Quantitative agreements for the atomwise radial distribution functions, the self-diffusion coefficients, and the neutron and x-ray diffraction scattering functions over a wide range of experimental conditions can be obtained, thus validating the ab initio force field without using experimental data a priori.

We investigate a immunoassay biosensor that employs a Quartz Crystal Microbalance (QCM) to detect the specific binding reaction of the (Human IgG1)-(Anti-Human IgG1) protein pair under physiological conditions. In addition to experiments, a three dimensional time domain finite element method (FEM) was used to perform simulations for the biomolecular binding reaction in microfluidic channels. In particular, we discuss the unsteady convective diffusion in the transportation tube, which conveys the buffer solution containing the analyte molecules into the micro-channel where the QCM sensor lies. It is found that the distribution of the analyte concentration in the tube is strongly affected by the flow field, yielding large discrepancies between the simulations and experimental results. Our analysis shows that the conventional assumption of the analyte concentration in the inlet of the micro-channel being uniform and constant in time is inadequate. In addition, we also show that the commonly used procedure in kinetic analysis for estimating binding rate constants from the experimental data would underestimate these rate constants due to neglected diffusion processes from the inlet to the reaction surface. A calibration procedure is proposed to supplement the basic kinetic analysis, thus yielding better consistency with experiments.

Intermolecular interaction energy data for the methane dimer have been calculated at a spectroscopic accuracy and employed to construct an ab initio potential energy surface (PES) for molecular dynamics (MD) simulations of fluid methane properties. The full potential curves of the methane dimer at 12 symmetric conformations were calculated by the supermolecule counterpoise-corrected second-order Møller-Plesset (MP2) perturbation theory. Single-point coupled cluster with single and double and perturbative triple excitations [CCSD(T)] calculations were also carried out to calibrate the MP2 potentials. We employed Pople's medium size basis sets [up to 6-311++G(3df, 3pd)] and Dunning's correlation consistent basis sets (cc-pVXZ and aug-cc-pVXZ, X = D, T, Q). For each conformer, the intermolecular carbon-carbon separation was sampled in a step 0.1 A for a range of 3-9 A, resulting in a total of 732 configuration points calculated. The MP2 binding curves display significant anisotropy with respect to the relative orientations of the dimer. The potential curves at the complete basis set (CBS) limit were estimated using well-established analytical extrapolation schemes. A 4-site potential model with sites located at the hydrogen atoms was used to fit the ab initio potential data. This model stems from a hydrogen-hydrogen repulsion mechanism to explain the stability of the dimer structure. MD simulations using the ab initio PES show quantitative agreements on both the atom-wise radial distribution functions and the self-diffusion coefficients over a wide range of experimental conditions., (Copyright 2008 Wiley Periodicals, Inc.)

The Jade Ribbon Campaign (JRC) is a culturally targeted, community-based outreach program to promote the prevention, early detection, and management of chronic hepatitis B virus (HBV) infection and liver cancer among Asian Americans. In 2001, 476 Chinese American adults from the San Francisco Bay Area attended an HBV screening clinic and educational seminar. The prevalence of chronic HBV infection was 13%; only 8% of participants showed serologic evidence of protective antibody from prior vaccination. Participants reported low preventive action before the clinic, but after one year, 67% of those with chronic HBV infection had consulted a physician for liver cancer screening, and 78% of all participants had encouraged family members to be tested for HBV. The increase in HBV awareness, screening, and physician follow-up suggests that culturally aligned interventions similar to the JRC may help reduce the disproportionate burden of disease to chronic HBV infection among Asian Americans.

Chronic hepatitis B in the Asian and Pacific Islander (API) population is among our nation's greatest ethnic and racial health disparities. Despite comprising 4.3% of the population, API make up a disproportionate half of the 1.2-2 million Americans living with chronic hepatitis B. As many as two-thirds of API are not aware of their infection because they have not been tested. This lack of knowledge prevents them from undergoing life-saving liver cancer screening and potential treatment. Likewise, those not protected are unaware that they should be vaccinated. Instead, there is a pervasive lack of awareness among API and healthcare providers. New concerted public health actions are needed to eliminate this major health disparity.

The ionization/dissociation mechanism of cyclopentanone has been experimentally investigated in molecular beam by irradiating with intense 394 and 788 nm laser fields with pulse duration of 90 fs. The range of laser intensities varied from 3 x 10(13) to 4 x 10(14) W/cm(2). For both wavelengths, the singly charged parent ion is observable while the doubly charged one cannot be found easily, although the fragmentation pattern supports its presence. Meanwhile, the extent of fragmentation at 788 nm is less than that in the 394 nm case. We quantitatively analyze the ionization processes of cyclopentanone in intense femtosecond laser by comparing the calculation results of ionization rate constants obtained from Ammosov-Delone-Krainov, Keldysh, and Keldysh-Faisal-Reiss (KFR) theories based on hydrogenlike atom model. We also compare the experimental and theoretical results; the generalized KFR theory is found to be useful in predicting the ionization yields of singly and doubly charged cyclopentanone ion. To interpret the dissociation patterns of the cyclopentanone ions, we have used the Rice-Ramsperger-Kassel-Marcus theory with the potential surfaces obtained from the ab initio quantum chemical calculations.

We investigate the characteristics of higher-lying band gaps for two-dimensional photonic crystals with large dielectric contrast. An optimal common band gap is attained on a hexagonal lattice of circular dielectric cylinders at relatively higher bands. The corresponding TM and TE modes exhibit simultaneous band edges, around which the frequency branches tend to be dispersionless. Unlike the fundamental band gap which usually appears between the dielectric and air bands, the optimal higher-lying gap in the present study occurs between two consecutive dielectric-like bands with high energy fill factors. The underlying mechanism is illustrated with the apparent change of eigenmode patterns inside the dielectric regions for both polarizations. In particular, the common gap region is bounded by two successive orders of Mie resonance frequencies on a single dielectric cylinder with the same geometry and material, where the Mie resonance modes show similar internal fields with the respective eigenmodes for the photonic crystal.

We have calculated the intermolecular interaction potentials of the silane dimer at the D3d conformation using the Hartree-Fock (HF) self-consistent theory, the correlation-corrected second-order Møller-Plesset (MP2) perturbation theory, and the density functional theory (DFT) with 108 functionals chosen from the combinations of 9 exchange and 12 correlation functionals. Single-point coupled cluster [CCSD(T)] calculations have also been carried out to calibrate the correlation effect. The HF calculations yield unbound potentials largely because of the exchange-repulsion interaction. In the MP2 calculations, the basis set effects on the repulsion exponent, the equilibrium bond length, the binding energy, and the asymptotic behavior of the calculated intermolecular potentials have been thoroughly studied. We have employed basis sets from the Slater type orbitals fitted with Gaussian functions (STO-nG, n = 3 approximately 6), Pople's medium size basis sets [up to 6-311++G(3df,3pd)], to Dunning's correlation consistent basis sets (cc-pVXZ and aug-cc-pVXZ, X = D, T, Q). With increasing basis size, the repulsion exponent and the equilibrium bond length converge at the 6-31G** basis set and the 6-311++G(3d,3p) basis set, respectively, while a large basis set (aug-cc-pVTZ) is required to converge the binding energy at a chemical accuracy ( approximately 0.05 kcal/mol). Up to the largest basis set used, the asymptotic dispersion coefficient has not converged to the expected C6 value from molecular polarizability calculations. We attribute the slow convergence partly to the inefficacy of using the MP2 calculations with Gaussian type functions to model the asymptotic behavior. Both the basis set superposition error (BSSE) corrected and uncorrected results are presented to emphasize the importance of including such corrections. Only the BSSE corrected results systematically converge to the expected potential curve with increasing basis size. The DFT calculations generate a wide range of interaction patterns, from purely unbound to strongly bound, underestimating or overestimating the binding energy. The binding energies calculated using the OPTXHCTH147, PBEVP86, PBEP86, PW91TPSS, PW91PBE, and PW91PW91 functionals and the equilibrium bond lengths calculated using the MPWHCTH93, TPSSHCTH, PBEVP86, PBEP86, PW91TPSS, PW91PBE, and PW91PW91 functionals are close to the MP2 results using the 6-311++G(3df,3pd) basis set. A correlation between the calculated DFT potentials and the exchange and correlation enhancement factors at the low-density region has been elucidated. The asymptotic behaviors of the DFT potentials are also analyzed.