Maximizing the Potential of Air National Guard International Health Specialists for Global Health Engagement.

The Air Force International Health Specialist program provides expert medical and public health support to enhance global health engagement efforts. National Guardsmen possess unique civilian health care expertise to support global health engagement. The DoD must increase support for Air National Guard International Health Specialist involvement, including training and development opportunities.

Microwave Facilitated Covalent Organic Framework/Transition Metal Dichalcogenide Heterostructures.

Organic/inorganic heterostructures present a versatile platform for creating materials with new functionalities and hybrid properties. In particular, junctions between two dimensional materials have demonstrated utility in next generation electronic, optical, and optoelectronic devices. This work pioneers a microwave facilitated synthesis process to readily incorporate few-layer covalent organic framework (COF) films onto monolayer transition metal dichalcogenides (TMDC). Preferential microwave excitation of the monolayer TMDC flakes result in selective attachment of COFs onto the van der Waals surface with film thicknesses between 1 and 4 nm. The flexible process is extended to multiple TMDCs (MoS2, MoSe2, MoSSe) and several well-known COFs (TAPA-PDA COF, TPT-TFA-COF, and COF-5). Photoluminescence studies reveal a power-dependent defect formation in the TMDC layer, which facilitates electronic coupling between the materials at higher TMDC defect densities. This coupling results in a shift in the A-exciton peak location of MoSe2, with a red or blue shift of 50 or 19 meV, respectively, depending upon the electron donating character of the few-layer COF films. Moreover, optoelectronic devices fabricated from the COF-5/TMDC heterostructure present an opportunity to tune the PL intensity and control the interaction dynamics within inorganic/organic heterostructures.

Piezoelectricity across 2D Phase Boundaries.

Piezoelectricity in low-dimensional materials and metal-semiconductor junctions has attracted recent attention. Herein, a 2D in-plane metal-semiconductor junction made of multilayer 2H and 1T' phases of molybdenum(IV) telluride (MoTe2 ) is investigated. Strong piezoelectric response is observed using piezoresponse force microscopy at the 2H-1T' junction, despite that the multilayers of each individual phase are weakly piezoelectric. The experimental results and density functional theory calculations suggest that the amplified piezoelectric response observed at the junction is due to the charge transfer across the semiconducting and metallic junctions resulting in the formation of dipoles and excess charge density, allowing the engineering of piezoelectric response in atomically thin materials.

Laser-Fabricated 2D Molybdenum Disulfide Electronic Sensor Arrays for Rapid, Low-Cost, Ultrasensitive Detection of Influenza A and SARS-Cov-2.

Multiplex electronic antigen sensors for detection of SARS-Cov-2 spike glycoproteins and hemagglutinin from influenza A are fabricated using scalable processes for straightforward transition to economical mass-production. The sensors utilize the sensitivity and surface chemistry of a 2D MoS2 transducer for attachment of antibody fragments in a conformation favorable for antigen binding with no need for additional linker molecules. To make the devices, ultra-thin layers (3 nm) of amorphous MoS2 are sputtered over pre-patterned metal electrical contacts on a glass chip at room temperature. The amorphous MoS2 is then laser annealed to create an array of semiconducting 2H-MoS2 transducer regions between metal contacts. The semiconducting crystalline MoS2 region is functionalized with monoclonal antibody fragments complementary to either SARS-CoV-2 S1 spike protein or influenza A hemagglutinin. Quartz crystal microbalance experiments indicate strong binding and maintenance of antigen avidity for antibody fragments bound to MoS2. Electrical resistance measurements of sensors exposed to antigen concentrations ranging from 2-20 000 pg mL-1 reveal selective responses. Sensor architecture is adjusted to produce an array of sensors on a single chip suited for detection of analyte concentrations spanning six orders of magnitude from pg mL-1 to µg mL-1.

Coherent Scattering of Low Mass Dark Matter from Optically Trapped Sensors.

We propose a search for low mass dark matter particles through momentum recoils caused by their scattering from trapped, nanometer-scale objects. Our projections show that even with a modest array of femtogram-mass sensors, parameter space beyond the reach of existing experiments can be explored. The case of smaller, attogram-mass sensors is also analyzed-where dark matter can coherently scatter from the entire sensor-enabling a large enhancement in the scattering cross-section relative to interactions with single nuclei. Large arrays of such sensors have the potential to investigate new parameter space down to dark matter masses as low as 10 keV. If recoils from dark matter are detected by such sensors, their inherent directional sensitivity would allow an unambiguous identification of a dark matter signal.

Trapped Electrons and Ions as Particle Detectors.

Electrons and ions trapped with electromagnetic fields have long served as important high-precision metrological instruments, and more recently have also been proposed as a platform for quantum information processing. Here we point out that these systems can also be used as highly sensitive detectors of passing charged particles, due to the combination of their extreme charge-to-mass ratio and low-noise quantum readout and control. In particular, these systems can be used to detect energy depositions many orders of magnitude below typical ionization scales. As illustrations, we suggest some applications in particle physics. We outline a nondestructive time-of-flight measurement capable of sub-eV energy resolution for slowly moving, collimated particles. We also show that current devices can be used to provide competitive sensitivity to models where ambient dark matter particles carry small electric millicharges ≪e. Our calculations may also be useful in the characterization of noise in quantum computers coming from backgrounds of charged particles.

Search for Composite Dark Matter with Optically Levitated Sensors.

Results are reported from a search for a class of composite dark matter models with feeble long-range interactions with normal matter. We search for impulses arising from passing dark matter particles by monitoring the mechanical motion of an optically levitated nanogram mass over the course of several days. Assuming such particles constitute the dominant component of dark matter, this search places upper limits on their interaction with neutrons of α_{n}≤1.2×10^{-7} at 95% confidence for dark matter masses between 1 and 10 TeV and mediator masses m_{ϕ}≤0.1 eV. Because of the large enhancement of the cross section for dark matter to coherently scatter from a nanogram mass (∼10^{29} times that for a single neutron) and the ability to detect momentum transfers as small as ∼200 MeV/c, these results provide sensitivity to certain classes of composite dark matter models that substantially exceeds existing searches, including those employing kilogram- or ton-scale targets. Extensions of these techniques can enable directionally sensitive searches for a broad class of previously inaccessible heavy dark matter candidates.

2D Electrets of Ultrathin MoO2 with Apparent Piezoelectricity.

Since graphene, a variety of 2D materials have been fabricated in a quest for a tantalizing combination of properties and desired physiochemical behavior. 2D materials that are piezoelectric, i.e., that allow for a facile conversion of electrical energy into mechanical and vice versa, offer applications for sensors, actuators, energy harvesting, stretchable and flexible electronics, and energy storage, among others. Unfortunately, materials must satisfy stringent symmetry requirements to be classified as piezoelectric. Here, 2D ultrathin single-crystal molybdenum oxide (MoO2 ) flakes that exhibit unexpected piezoelectric-like response are fabricated, as MoO2 is centrosymmetric and should not exhibit intrinsic piezoelectricity. However, it is demonstrated that the apparent piezoelectricity in 2D MoO2 emerges from an electret-like behavior induced by the trapping and stabilization of charges around defects in the material. Arguably, the material represents the first 2D electret material and suggests a route to artificially engineer piezoelectricity in 2D crystals. Specifically, it is found that the maximum out-of-plane piezoresponse is 0.56 pm V-1 , which is as strong as that observed in conventional 2D piezoelectric materials. The charges are found to be highly stable at room temperature with a trapping energy barrier of ≈2 eV.

Predisposing Factors and Outcomes After Prolonged Admission Following Hip Fracture.

Introduction Hip fractures are increasingly prevalent and can result in substantial morbidity, mortality, and cost. Despite the existence of enhanced management strategies, prolonged hip fracture admissions persist. This study's objective was to ascertain characteristics associated with a prolonged length of stay (LOS) and quantify return to baseline once discharged. Methods A retrospective audit of hip fractures over a four-year period was conducted, identifying patients with a LOS over 100 days. Demographics, comorbidities, pre- and post-admission function, and status were assessed. Patients sustaining inpatient hip fractures were excluded to negate the effect of initial admission on LOS. Results Seven hundred and eleven hip fractures were treated, of which 48 (6.8%) were suitable for inclusion. The patients' median age and LOS was 83.5 years and 153 days, respectively. Preoperative American Society of Anesthesiologists - Physical Status (ASA-PS) Grades II and III predominated at 41.7% and 39.6%, respectively. Eighteen of patients had a diagnosis of dementia before admission, increasing to 29 on discharge (P = 0.0026). One patient was in long-term care prior to admission, rising to 30 on discharge (P < 0.0001), with only 25.6% returning to pre-admission residential status (P < 0.0001). Nineteen patients were mobilising unaided prior to admission, decreasing to only two following discharge, with a mere 37.1% returning to their pre-admission mobility baseline (P < 0.0001). Discussion Hip fracture patients with multiple comorbidities or a diagnosis of dementia were most likely to have a prolonged LOS which, in turn, impacted upon return to baseline mobility, cognitive status, and independence. Early identification and management of this cohort may help reduce the potential disease burden and economic effects that a prolonged LOS creates.

Postoperative Complications of Patients With Spina Bifida Undergoing Urologic Laparotomy: A Multi-institutional Analysis.

OBJECTIVE: To characterize perioperative morbidity and mortality in adult patients with spina bifida undergoing laparotomy. PATIENTS AND METHODS: We retrospectively studied the postoperative complications of 59 operations of patients with spina bifida undergoing abdominal laparotomies for urologic indications at 3 institutions. We evaluated postoperative complications using the Clavien-Dindo classification scale. RESULTS: The overall complication rate was 91.5%. The most common complications were ileus, pressure ulcers, urinary tract infection, and wound infection. Over 40% of the patients developed a class 3 or 4 complication requiring subsequent surgery or intensive care unit admission. The hospital readmission rate was 42% and was correlated with higher-grade complications. On multivariable analysis, only older age was significantly associated with grade of complication. CONCLUSION: These data demonstrate that adult patients with spina bifida comprise a unique population that faces an extremely high surgical risk even in centers of excellence. As patients with spina bifida live longer lives, thanks to modern medicine, there is a timely opportunity for research on perioperative management in these patients to improve postsurgical outcomes.

Search for Screened Interactions Associated with Dark Energy below the 100 µm Length Scale.

We present the results of a search for unknown interactions that couple to mass between an optically levitated microsphere and a gold-coated silicon cantilever. The scale and geometry of the apparatus enable a search for new forces that appear at distances below 100 µm and which would have evaded previous searches due to screening mechanisms. The data are consistent with electrostatic backgrounds and place upper limits on the strength of new interactions at <0.1 fN in the geometry tested. For the specific example of a chameleon interaction with an inverse power law potential, these results exclude matter couplings ß>5.6×10^{4} in the region of parameter space where the self-coupling Λ≳5 meV and the microspheres are not fully screened.

Use of Botulinum Toxin A in the Treatment of Lower Urinary Tract Disorders: A Review of the Literature.

Botulinum neurotoxin (BoNT) is used to treat a variety of ailments, and its therapeutic application in lower urinary tract disorders (LUTDs) is well studied. Robust evidence supporting the efficacy and tolerability of BoNT in the treatment of neurogenic detrusor overactivity (NDO) and non-neurogenic overactive bladder (OAB) has led to regulatory approval for these conditions. Use of BoNT in the treatment of interstitial cystitis/bladder pain syndrome, chronic pelvic pain, and detrusor sphincter dyssynergia has demonstrated some promise, but is still evolving and off-label for these indications. Trials to date do not support the use of BoNT for benign prostatic hyperplasia. This comprehensive review outlines the mechanisms of BoNT in the treatment of LUTDs in adults and presents background and updated data examining the efficacy and adverse events associated with the use of BoNT in common urologic applications.

Obesity does not affect survival outcomes in extremity soft tissue sarcoma.

BACKGROUND: Obesity is a growing epidemic and has been associated with an increased frequency of complications after various surgical procedures. Studies also have shown adipose tissue to promote a microenvironment favorable for tumor growth. Additionally, the relationship between obesity and prognosis of soft tissue sarcomas has yet to be evaluated. QUESTIONS/PURPOSES: We sought to assess if (1) obesity affects survival outcomes (local recurrence, distant metastasis, and death attributable to disease) in patients with extremity soft tissue sarcomas; and (2) whether obesity affected wound healing and other surgical complications after treatment. METHODS: A BMI of 30 kg/m(2) or greater was used to define obesity. Querying our prospective database between 2001 and 2008, we identified 397 patients for the study; 154 were obese and 243 were not obese. Mean followup was 4.5 years (SD, 3.1 years) in the obese group and 3.9 years (SD, 3.2 years) in the nonobese group; the group with a BMI of 30 kg/m(2) or greater had a higher proportion of patients with followups of at least 2 years compared with the group with a BMI less than 30 kg/m(2) (76% versus 62%). Outcomes, including local recurrence, distant metastasis, and overall survival, were analyzed after patients were stratified by BMI. Multivariable survival models were used to identify independent predictors of survival outcomes. Wilcoxon rank sum test was used to compare continuous variables. Based on the accrual interval of 8 years, the additional followup of 5 years after data collection, and the median survival time for the patients with a BMI less than 30 kg/m(2) of 3 years, we were able to detect true median survival times in the patients with a BMI of 30 kg/m(2) of 2.2 years or less with 80% power and type I error rate of 0.05. RESULTS: Patients who were obese had similar survival outcomes and wound complication rates when compared with their nonobese counterparts. Patients who were obese were more likely to have lower-grade tumors (31% versus 20%; p = 0.021) and additional comorbidities including diabetes mellitus (26% versus 7%; p < 0.001), hypertension (63% versus 38%; p < 0.001), and smoking (49% versus 37%; p = 0.027). Regression analysis confirmed that even after accounting for certain tumor characteristics and comorbidities, obesity did not serve as an independent risk factor in affecting survival outcomes. CONCLUSIONS: Although the prevalence of obesity continues to increase and lead to many negative health consequences, it does not appear to adversely affect survival, local recurrence, or wound complication rates for patients with extremity soft tissue sarcomas. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.

Search for millicharged particles using optically levitated microspheres.

We report results from a search for stable particles with charge ≳10^{-5}e in bulk matter using levitated dielectric microspheres in high vacuum. No evidence for such particles was found in a total sample of 1.4 ng, providing an upper limit on the abundance per nucleon of 2.5×10^{-14} at the 95% confidence level for the material tested. These results provide the first direct search for single particles with charge ≲0.1e bound in macroscopic quantities of matter and demonstrate the ability to perform sensitive force measurements using optically levitated microspheres in vacuum.

Gunshot victims at a major level I trauma center: a study of 343,866 emergency department visits.

BACKGROUND: Disturbing trends regarding the sex, age, and race of gunshot victims have been reported in previous national studies; however, gunshot trends have not been well documented in individual cities in the southeastern United States. OBJECTIVES: 1) Analyze trends in gunshot wounds, particularly the association between gunshot wounds and race, among victims presenting to a Level I Trauma Center in Middle Tennessee; 2) Compare specific characteristics of gunshot victims to the general Emergency Department (ED) population. METHODS: This is a retrospective cohort study of 343,866 ED visits from 2004 to 2009. RESULTS: Compared to the general ED population, gunshot victims were more predominantly male (87.5% vs. 43.4%), black (57.6% vs. 29.5%), younger (47.8% under age 25 years vs. 31.6%), and demonstrated higher Medicaid enrollment (78.6% vs. 44.7%). The majority of black gunshot victims were aged 18-25 years (47.1%) and victims of assault (65.9%). Non-black gunshot victims suffered more unintentional (40.2% vs. 28.2%) and self-inflicted (9.1% vs. 0.4%) injuries and were more evenly distributed among ages 18-55 years. Black patients were 3.03 (95% confidence interval 2.93-3.14) times more likely to present to this ED for gunshot wounds than non-black patients, after controlling for age, sex, and insurance status (p < 0.001). CONCLUSIONS: Our study demonstrates that black patients between 18 and 25 years of age presenting to this trauma center are more likely to be victims of gun violence than their non-black counterparts. Our study evaluates trends in gun violence in the Southeast, particularly in relation to race, age, and insurance status.

Staples equal sutures for skin closure after soft tissue tumor resection.

BACKGROUND: Wound closure accounts for a relatively constant portion of the time required to complete a surgical case. Both longer closure times and wound infections contribute to higher medical costs and patient morbidity. QUESTIONS/PURPOSES: We therefore determined whether (1) biologic and treatment factors greater influenced wound healing than the choice of sutures or staples; and (2) different times to closure affected cost when sutures or staples are used in patients with musculoskeletal tumors. METHODS: We retrospectively reviewed 511 patients who had sarcoma resections of the buttock, thigh, and femur from 2003 to 2010; 376 had closure with sutures and 135 with staples. Data were abstracted on patient demographics, comorbidities, select procedural data, and wound complications. Wound complications were defined by hospitalization within 6 months postoperatively for a wound problem, irrigation and débridement, or infection treated with antibiotics. We determined the association between staples versus sutures and wound complications after controlling for confounding factors. The minimum followup was 2 weeks. A prospective, timed analysis of wounds closed with either sutures or staples was also performed. RESULTS: We found an association between obesity and radiation and wound complications. Wounds were closed an average of 5.3 minutes faster with staples than with suture (0.29 minutes versus 5.6 minutes, respectively), saving a mean 2.1% of the total operating time although the total operating time was similar in the two groups. CONCLUSIONS: We found no difference in wound complications after closure with sutures or staples, although obesity and radiation treatment appear to affect wound outcomes. Data suggest that time saved in the operating room by closing with staples compensates for added material costs and does not compromise wound care in patients with lower extremity sarcomas. LEVEL OF EVIDENCE: Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

An evaluation of immediate-use steam sterilization practices in adult knee and hip arthroplasty procedures.

BACKGROUND: Immediate-use steam sterilization (IUSS) is a safe method to sterilize emergently contaminated instruments, but inappropriate use may lead to an increased risk for surgical site infection. This study aimed to identify risk factors, rationale, and variability in procedural adherence in cases of IUSS. METHODS: This retrospective, case-control study compared adult patients undergoing hip and knee arthroplasty in which IUSS was (n = 104) and was not (n = 81) performed. RESULTS: Multivariate analysis revealed 4 predictive risk factors for IUSS: history of malignancy (odds ratio [OR], 3.2 [95% confidence interval (CI) 1.1-9.3]), obesity (OR, 2.3 [95% CI: 1.02-5.2]), procedure performed in operating room 13 (OR, 2.5 [95% CI: 1.2-5.4]), and Monday procedure (OR, 3.6 [95% CI: 1.4-9.1]). The only factor that protected against IUSS was performing the procedure in the morning (OR, 0.4 [95% CI: 0.2-0.96]). Only 9.5% of cases of IUSS involved an acceptable indication. Documented adherence to core practices was also variable. CONCLUSION: Several patient- and case-specific factors can help predict the incidence of IUSS. Furthermore, practices should be hardwired to ensure IUSS is utilized for the correct indication. Documentation must be improved to allow institutions to accurately track IUSS.