Increased Time Interval of Postoperative Flap Monitoring After Autologous Breast Reconstruction.

BACKGROUND: Hourly flap checks are the most common means of flap monitoring during the first 24 hours following autologous breast reconstruction (ABR). This practice often requires intensive care unit (ICU) admission, which is a key driver of health care costs and decreased patient satisfaction. This study addresses these issues by demonstrating decreased cost and length of admission associated with a 4-hour interval between flap checks during the first 24 hours following ABR. METHODS: This is a retrospective review of ABR surgeries performed by multiple surgeons from 2017 to 2020. Two cohorts were identified, one that underwent flap checks every hour in the ICU (Q1 cohort) and the other that underwent flap checks every 4 hours on the hospital floor (Q4 cohort). Our primary outcome measures were length of stay (LOS), flap takebacks, flap loss, and encounter cost. RESULTS: Rates of flap takeback and loss did not differ between cohorts (P = 0.18, P = 0.21). The Q4 cohort's average LOS was shorter than the Q1 cohort (P = 0.002). The Q4 cohort's average cost was also $25,554.80 less than the Q1 cohort (P < 0.001). This association persisted after controlling for LOS, operating room takeback, timing and laterality of reconstruction, and flap configuration (hazard ratio = 0.65, P = 0.0007). CONCLUSION: This study demonstrates the benefits of lengthened flap check intervals during the first 24 hours following ABR. These intervals decrease the cost of ABR while also maintaining safety, making ABR a more accessible option for breast reconstruction patients.

Spectroscopic Identification of the Charge Transfer State in Thiophene/Fullerene Heterojunctions: Electroabsorption Spectroscopy from GW/BSE Calculations.

Creation of charge transfer (CT) states in bulk heterojunction systems such as C60/polymer blends is an important intermediate step in the creation of carriers in organic photovoltaic systems. CT states generally have small oscillator strengths in linear optical absorption spectroscopy owing to limited spatial overlap of electron and hole wave functions in the CT excited state. Electroabsorption spectroscopy (EA) exploits changes in wave function character of CT states in response to static electric fields to enhance detection of CT states via nonlinear optical absorption spectroscopies. A 4 × 4 model Hamiltonian is used to derive splittings of even and odd Frenkel (FR) excited states and changes in wave function character of CT excited states in an external electric field. These are used to explain why FR and CT states yield EA lineshapes which are first and second derivatives of the linear optical absorption spectrum. The model is applied to ammonia-borane molecules and pairs of molecules with large and small B-N separations and CT or FR excited states. EA spectra are obtained from differences in linear optical absorption spectra in the presence or absence of a static electric field and from perturbative sum over states (SOS) configuration interaction singles χ(2) and χ(3) nonlinear susceptibility calculations. Good agreement is found between finite field (FF) and SOS methods at field strengths similar to those used in EA experiments. EA spectra of three C60/oligothiophene complexes are calculated using the SOS method combined with GW/BSE methods. For these C60/oligothiophene complexes, we find several CT states in a narrow energy range in which charge transfer from the thiophene HOMO level to several closely spaced C60 acceptor levels yields an EA signal around 10% of the signal from oligothiophene.

Regenerative vs flap-based limb salvage: a multi-centered, prospective, randomized controlled trial.

Aim: The goal of this study was to compare success rates of a regenerative limb salvage approach (rLS) using dehydrated human chorion amnion membrane (dHACM) to traditional flap-based limb salvage (fLS). Materials & methods: This prospective RTC enrolled patients presenting with complex extremity wounds over a 3-year period. Primary outcomes included success of primary reconstruction, persistence of exposed structures, time to definitive closure, and time to weight bearing. Results: Patients meeting inclusion criteria were randomized to fLS (n = 14) or rLS (n = 25). The primary reconstructive method was successful for 85.7% of fLS subjects and 80% of rLS subjects (p = 1.00). Conclusion: This trial provides strong evidence that rLS is an effective option in the setting of complex extremity wounds, with success rates comparable to traditional flaps. Clinical Trial Registration: NCT03521258 (ClinicalTrials.gov).

Chronic and traumatic wounds may result in loss of limb without appropriate medical treatment. Traditionally large wounds with exposed bone or other important structures require surgery to transfer healthy soft tissue (a tissue flap) from one area of the body to the defect created by the wound. Our study seeks to demonstrate an approach to similar wounds using a biologic dressing to avoid extensive surgery. We demonstrate that this biologic dressing made from human membranes has a similar success rate to flap surgery for achieving wound healing.

Autologous Heterogeneous Skin Construct Closes Traumatic Lower Extremity Wounds in Pediatric Patients: A Retrospective Case Series.

Lower extremity traumatic wounds pose unique challenges in pediatric patients, including vessel caliber, compliance with postoperative instructions, parental concerns about multiple operations, and long-term function. An autologous heterogeneous skin construct (AHSC) has demonstrated the ability to cover avascular structures and regenerate full-thickness functional skin. The objective of this study is to report our experience using AHSC in a cohort of pediatric trauma patients. This study is a noncontrolled, retrospective cohort analysis of all pediatric patients (<19 years of age) treated with AHSC for lower extremity traumatic wounds with at least one exposed deep structure (tendon, bone, and/or joint) at a single institution between May 1, 2018, and April 1, 2019. Seven patients with 10 traumatic wounds met inclusion criteria. The median follow-up time was 11.8 months. Five patients were male (71%); the median age was 7 years (range = 2-15 years). Average wound size was 105 cm2. All wounds achieved coverage of exposed structures and epithelial closure in a median of 13 and 69 days, respectively. There were no donor site complications and no reoperations required. All patients returned to normal activity, ambulate without limp, can wear shoes normally, and have normal tendon gliding. AHSC covered exposed structures and achieved closure within a single application in complex traumatic lower extremity wounds in a pediatric cohort.

Charge transfer excitons in π-stacked thiophene oligomers and P3[Alkyl]T crystals: CIS calculations and electroabsorption spectroscopy.

Poly(3-alkylthiophenes) (P3[Alkyl]T) exhibit high mobility and efficiency of formation of polaronic charge carriers generated by light absorption, thus finding applications in field effect devices. Excited states of π-stacked dimers of tetra-thiophene oligomers (T4), infinite isolated polythiophene (PT) chains, and P3[Alkyl]T crystals are modeled using configuration interaction singles (CIS) calculations. Excited states in cofacial T4 dimers are mostly localized Frenkel states except for two low energy charge transfer (CT) exciton states, which become the ionization potential and electron affinity levels of T4 molecules at large dimer separation. The lowest excited states in infinite, isolated PT chains and P3[Alkyl]T crystals are intra-chain excitons where the electron and hole are localized on the same chain. The next lowest excited states are interchain, CT excitons in which the electron and hole reside on neighboring chains. The former capture almost all optical oscillator strength and the latter may be a route to efficient formation of polaronic charge carriers in P3[Alkyl]T systems. Changes in optical absorption energies of T4 dimers as a function of molecular separation are explained using CIS calculations with four frontier orbitals in the active space. Shifts in optical absorption energy observed on going from isolated chains to P3[Alkyl]T lamellar structures are already present in single-particle transition energies induced by direct π-π interactions at short range. The electroabsorption spectrum of T4 dimers is calculated as a function of dimer separation and states that are responsible for parallel and perpendicular components of the spectrum are identified.

Many-body theory of positron binding to polyatomic molecules.

Positron binding to molecules is key to extremely enhanced positron annihilation and positron-based molecular spectroscopy1. Although positron binding energies have been measured for about 90 polyatomic molecules1-6, an accurate ab initio theoretical description of positron-molecule binding has remained elusive. Of the molecules studied experimentally, ab initio calculations exist for only six; these calculations agree with experiments on polar molecules to at best 25 per cent accuracy and fail to predict binding in nonpolar molecules. The theoretical challenge stems from the need to accurately describe the strong many-body correlations including polarization of the electron cloud, screening of the electron-positron Coulomb interaction and the unique process of virtual-positronium formation (in which a molecular electron temporarily tunnels to the positron)1. Here we develop a many-body theory of positron-molecule interactions that achieves excellent agreement with experiment (to within 1 per cent in cases) and predicts binding in formamide and nucleobases. Our framework quantitatively captures the role of many-body correlations and shows their crucial effect on enhancing binding in polar molecules, enabling binding in nonpolar molecules, and increasing annihilation rates by 2 to 3 orders of magnitude. Our many-body approach can be extended to positron scattering and annihilation γ-ray spectra in molecules and condensed matter, to provide the fundamental insight and predictive capability required to improve materials science diagnostics7,8, develop antimatter-based technologies (including positron traps, beams and positron emission tomography)8-10, and understand positrons in the Galaxy11.

Behavioral and inflammatory sex differences revealed by celecoxib nanotherapeutic treatment of peripheral neuroinflammation.

Neuropathic pain affects millions of people worldwide, yet the molecular mechanisms of how it develops and persists are poorly understood. Given that males have historically been utilized as the primary sex in preclinical studies, less is known about the female neuroinflammatory response to injury, formation of pain, or response to pain-relieving therapies. Macrophages contribute to the development of neuroinflammatory pain via the activation of their cyclooxygenase-2 (COX-2) enzyme, which leads to the production of prostaglandin E2 (PGE2). PGE2 activates nociception and influences additional leukocyte infiltration. Attenuation of COX-2 activity decreases inflammatory pain, most commonly achieved by nonsteroidal anti-inflammatory drugs (NSAIDs), yet NSAIDs are considered ineffective for neuropathic pain due to off target toxicity. Using chronic constriction injury of the rat sciatic nerve, we show that males and females exhibit quantitatively the same degree of mechanical allodynia post injury. Furthermore, a low-dose nanotherapeutic containing the NSAID celecoxib is phagocytosed by circulating monocytes that then naturally accumulate at sites of injury as macrophages. Using this nanotherapeutic, we show that treated males exhibit complete reversal of hypersensitivity, while the same dose of nanotherapeutic in females provides an attenuated relief. The difference in behavioral response to the nanotherapy is reflected in the reduction of infiltrating macrophages at the site of injury. The observations contained in this study reinforce the notion that female neuroinflammation is different than males.

Stratification of Surgical Risk in DIEP Breast Reconstruction Based on Classification of Obesity.

BACKGROUND: From both a medical and surgical perspective, obese breast cancer patients are considered to possess higher risk when undergoing autologous breast reconstruction relative to nonobese patients. However, few studies have evaluated the continuum of risk across the full range of obesity. This study sought to compare surgical risk between the three World Health Organization (WHO) classes of obesity in patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction. METHODS: A retrospective review of 219 obese patients receiving 306 individual DIEP flaps was performed. Subjects were stratified into WHO obesity classes I (body mass index [BMI]: 30-34), II (BMI: 35-39), and III (BMI: ≥ 40) and assessed for risk factors and postoperative donor and recipient site complications. RESULTS: When examined together, the rate of any complication between the three groups only trended toward significance (p = 0.07), and there were no significant differences among rates of specific individual complications. However, logistic regression analysis showed that class III obesity was an independent risk factor for both flap (odds ratio [OR]: 1.71, 95% confidence interval [CI]: 0.91-3.20, p = 0.03) and donor site (OR: 2.34, 95% CI: 1.09-5.05, p = 0.03) complications. CONCLUSION: DIEP breast reconstruction in the obese patient is more complex for both the patient and the surgeon. Although not a contraindication to undergoing surgery, obese patients should be diligently counseled regarding potential complications and undergo preoperative optimization of health parameters. Morbidly obese (class III) patients should be approached with additional caution, and perhaps even delay major reconstruction until specific BMI goals are met.

Single Staged Mastopexy With Autologous Fat Grafting: An Alternative to Augmentation Mastopexy With Implants.

BACKGROUND: Improving the ptotic breast with mastopexy and restoring upper pole fullness with augmentation continues to be a challenging issue for plastic surgeons. Autologous fat grating (AFG) for shaping and contouring of implant augmented breasts has shown positive outcomes with few complications. OBJECTIVES: The objective of this study was to evaluate our experience with combined mastopexy and fat grafting for women with existing breast ptosis who prefer not to receive prosthetic breast implants but do desire volume enhancement. METHODS: A retrospective review of patients undergoing a single staged mastopexy with AFG, from 2006 to 2017, was performed. Inclusion criteria were women with breast ptosis or tuberous breasts desiring improved breast shape and volume. Patients were excluded if they were undergoing implant removal before the procedure. Clinical aesthetic outcomes were assessed by fellow plastic surgeons according to the Telemark Breast Scoring system. RESULTS: A total of 284 breasts, in 140 women, underwent a single staged mastopexy with AFG. The mean amount of fat grafted per breast was 299.4 mL (range, 50-710 mL). There were no surgical site infections, hematomas, or seromas. There were 3 major and 8 minor (0.06%) postoperative breast complications. A total of 13 plastic surgeons, of the 183 invited (7.1%), completed the breast outcomes survey. Regarding each category, there was significant improvement (P ≤ 0.0001) in upper pole fullness, ptosis, overall aesthetics, and symmetry postoperatively. CONCLUSIONS: AFG combined with mastopexy is not associated with significant postoperative complications and results in excellent breast aesthetic outcomes.

American Society of Plastic Surgeons Member Post-Operative Opioid Prescribing Patterns.

INTRODUCTION: Despite the widespread use of opioids in pain management, there are currently no evidence-based guidelines for the treatment of postoperative pain with opioids. Although other surgical specialties have begun researching their pain prescribing patterns, there has yet to be an investigation to unravel opioid prescribing patterns among plastic surgeons. METHODS: Survey Monkey was used to sample the American Society of Plastic Surgeons (ASPS) members regarding their opioid prescribing practice patterns. The survey was sent randomly to 50% of ASPS members. Respondents were randomized to 1 of 3 different common elective procedures in plastic surgery: breast augmentation, breast reduction, and abdominoplasty. RESULTS: Of the 5,770 overall active ASPS members, 298 responses (12% response rate) were received with the following procedure randomization results: 106 for breast augmentation, 99 for breast reduction, and 95 for abdominoplasty. Overall, 80% (N = 240) of respondents used nonnarcotic adjuncts to manage postoperative pain, with 75.4% (N = 181) using nonnarcotics adjuncts >75% of the time. The most commonly prescribed narcotics were Hydrocodone with Acetaminophen (Lortab, Norco) and Oxycodone with Acetaminophen (Percocet, Oxycocet) at 42.5% (N = 116) and 38.1% (N = 104), respectively. The most common dosage was 5 mg (80.4%; N = 176), with 48.9% (N = 107) mostly dispensing 20-30 tablets, and the majority did not give refills (94.5%; N = 207). CONCLUSIONS: Overall, plastic surgeons seem to be in compliance with proposed American College of Surgeon's opioid prescription guidelines. However, there remains a lack of evidence regarding appropriate opioid prescribing patterns for plastic surgeons.

Timing of Free Flaps for Traumatic Wounds of the Lower Extremity: Have Advances in Perioperative Care Changed the Treatment Algorithm?

BACKGROUND: Despite the landmark study by Godina 30 years ago, opinions still vary within the literature about the management of complex traumatic wounds in the lower extremity. We present a large series of lower extremity reconstructions with vascularized free tissue and examine the perioperative factors that influenced the success of these cases. METHODS: We reviewed 88 patients with free flap reconstruction of traumatic lower extremity wounds over 8 years. Primary outcomes were flap infections, flap loss, total flap-specific complications, and total recipient site complications. Independent variables specific to perioperative care including time to flap coverage, injury classification, exposed or infected hardware, prior osteomyelitis, use of wound vacuum-assisted closure (VAC) therapy, and concurrent polytrauma were investigated to establish their influence on primary outcomes. Each independent variable was assessed using Chi-square or Fisher's exact test and was included in a logistic regression analysis to establish significance. RESULTS: Of the 88 patients, 8 had flap loss, 8 had flap infections, and a total of 23 had primary adverse outcomes. Timing of the reconstruction, VAC use, injury classification, prior hardware or wound status, or presence of polytrauma had no statistically significant impact on the primary outcomes. Injury classification/severity on total recipient site complications (p = 0.051) and flap-specific complications (p = 0.073) trended toward significance; however, subgroup analysis did not achieve significance. Logistic regression of any recipient site complication including all independent variables similarly showed no significance. CONCLUSION: Although the original study by Godina suggests early coverage is critical to optimize outcomes, in the modern era of advanced wound care, our study adds to a growing body of evidence that supports the de-emphasis of the 72-hour reconstruction interval. Our current management is focused on more effectively coordinating efficient peritraumatic and perioperative care on an individualized basis in the often very complicated polytrauma patient.

Dynamic Histological Events and Molecular Changes in Excisional Wound Healing of Diabetic DB/DB Mice.

BACKGROUND: Wound contraction and re-epithelialization over the entire healing process had never been histologically examined daily in diabetic mouse wounds. Correlating morphological characters with molecular changes may be essential to understand the potential mechanism of impeded diabetic wound healing. MATERIALS AND METHODS: In 99 db/db and 63 db/m mice, dorsal-paired 8 mm-diameter wounds were created. Wound contraction and re-epithelialization were histologically analyzed daily-six wounds per group each day. A novel three-dimensional collagen gel model was used to study diabetic dermal fibroblast contractility. Fibroblast-to-myofibroblasts differentiation and TGFß-SMAD signaling pathway through the diabetic db/db wound healing process were studied by immunohistochemistry. RESULTS: Db/db wounds presented delayed closure with impaired wound contraction. Re-epithelialization was not slow but showed thinner epithelial formation and irregular keratinocyte arrangement. Diabetic dermal fibroblasts had significantly lower contractile ability than nondiabetic fibroblasts. In db/db wounds, α-SMA, the marker of myofibroblasts, showed constantly low through the healing, which represented reduced fibroblast-to-myofibroblasts differentiation. Remarkably weak staining of TGFßRI and low accumulation of Smad3 in nuclei were observed. CONCLUSIONS: We demonstrated and precisely located downregulated TGFß signaling pathway in db/db wounds by showing low expression of TGFßRI and failure of Smad3 translocation from cytoplasm to nuclei, which was not reported previously. The downregulated TGFß signaling pathway may contribute to the attenuated fibroblast-to-myofibroblast differentiation. Deficient re-epithelialization and defective wound contraction contribute principally to delayed healing of diabetic db/db wounds.

Single Versus Simultaneous Double Free Flaps for Head and Neck Reconstruction: Comparison of Flap Outcomes and Donor-Site Morbidity.

INTRODUCTION: Ablative procedures of the head and neck often result in substantial defects that require large-volume tissue transfer for restoration of form and function. Multiple simultaneous free flaps may be required for complex defects, but these procedures are often avoided because of the perception of an increase in associated surgical complications and morbidity. We present our experience with the use of simultaneous multiple free flaps as compared with single free flaps (SFFs) for head and neck reconstruction. METHODS: Thirty-seven patients with a history of head and neck malignancy underwent SFF reconstruction, and 21 patients underwent double free flap (DFF) reconstruction. Statistical analysis was conducted comparing demographics, comorbidities, etiology of disease, and surgical outcomes between the 2 patient groups. RESULTS: Operative time and length of hospital stay were both significantly longer in the DFF group versus the SFF group. Despite significantly higher rates of preoperative radiation, osteoradionecrosis, and operation for secondary malignancy in DFF group, no significant differences in flap survival, partial flap loss, recipient site complications, or donor site complications were found. Overall flap-related reoperation rates were low, as were total flap losses. There were 10 complications (24%) that required reoperation in the DFF group, and 1 total flap loss (2.4%), on per-flap basis. There were 10 complications (27%) that required reoperation in the SFF group and 3 total flap losses (8.1%). Per-flap incidence of donor site morbidity in the DFF group was significantly lower than that in the SFF group (23.8% vs 56.8%, respectively, P = 0.011). CONCLUSIONS: The use of multiple free flaps for reconstruction of major head and neck tissue defects is sometimes necessary to achieve adequate reconstructive results. These procedures have no significant associated increase in overall flap-related complications. Our findings suggest that donor site morbidity can be minimized in double-flap reconstructions by thoughtful flap selection.

Regeneration and expansion of autologous full-thickness skin through a self-propagating autologous skin graft technology.

New autologous skin regeneration technology yielded full-thickness skin as evidenced by clinical observation and skin biopsy 5 months after surgery, providing relief for debilitating split-thickness skin graft contracture in a pediatric burn case.

Assessing Age as a Risk Factor for Complications in Autologous Breast Reconstruction.

BACKGROUND: Breast cancer is primarily a diagnosis of older women. Many patients seeking breast reconstruction are elderly women (aged 65 years or older). However, many surgeons anecdotally believe that surgery in elderly patients is inherently dangerous, or at least prone to more complications. METHODS: The authors conducted a retrospective cohort study composed of chart review of all deep inferior epigastric perforator flap breast reconstruction patients at a single institution divided into an elderly cohort (65 years or older) and a nonelderly cohort (younger than 65 years). Cohort was the primary predictor variable. Demographic and comorbidity data were secondary predictor variables. Primary outcomes were complete flap loss, partial flap loss, or need for flap reexploration. Secondary outcomes such as wound healing problems, seroma, and others were also assessed. RESULTS: There were 285 flaps in the nonelderly cohort and 54 flaps in the elderly cohort. The elderly cohort had higher rates of diabetes, hypertension, and hyperlipidemia. Chi-square analysis showed no significant differences in primary outcomes between the two cohorts. Breast wound dehiscence was significantly higher in the elderly cohort (p < 0.01). On logistic regression, being elderly was seen as a significant risk factor for complete flap loss (OR, 10.92; 95 percent CI, 0.97 to 122.67; p = 0.05). The overall success rate for the nonelderly cohort was 99.6 percent, whereas the success rate for the nonelderly cohort was 96.3 percent. CONCLUSIONS: Elderly women desire breast reconstruction. Free flap breast reconstruction is a viable and safe procedure in these patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, II.

Cosmetic Surgeon Representation: Ensuring Board Certification Transparency and Patient Awareness.

BACKGROUND: Previous studies revealed that patients preferred plastic surgeons over cosmetic surgeons for surgical procedures, but few knew that any physician with a medical degree was legally qualified to perform cosmetic surgery. Results also indicated that a primary consideration for patients in selecting a surgeon was board certification. Although patient preferences concerning aesthetic surgery have previously been surveyed, no study examined a consumer's ability delineate between specialties based on Web sites. The purpose of this study was to investigate the responses of medical students to questions regarding a cosmetic and plastic surgeon's board certification. METHODS: A total of 4 cosmetic and 5 plastic surgeon Web sites were selected, in a single large city, from a Google search for the following procedures: liposuction, breast augmentation, blepharoplasty, rhytidectomy, and abdominoplasty. Screenshots of the Google search link, the page after clicking on the link, and the about the doctor page were collected to simulate an actual patient search experience. Four randomized surveys were created using screenshots and scenarios through Survey Monkey. Surveys were distributed and collected anonymously. Data analysis was accomplished using a chi-square test of independence (P < 0.05). RESULTS: A total of 474 medical students responded, and the difference between cosmetic and plastic surgeon variables was significant (P < 0.001). Upon comparison of different procedures, the cosmetic and plastic groups were found to be statistically different (P < 0.05), with some exceptions. On average, when presented with a plastic surgeon, 95.3% thought this was a board-certified plastic surgeon. When presented with a cosmetic surgeon, 54.3% also thought this was a board-certified plastic surgeon. The decline in responses regarding board certification, for the first and second cosmetic surgeons presented, was found to be statistically different (P < 0.0001). CONCLUSIONS: Over 50% of medical students had difficulty distinguishing between a cosmetic and plastic surgeon based on Web site advertisements; therefore, patients may have a more difficult experience. Results of this study prove the need for a universal definition, and patient education, relating to board certifications.

Dielectric Anisotropy of the GaP/Si(001) Interface from First-Principles Theory.

First-principles calculations of the dielectric anisotropy of the GaP/Si(001) interface are compared to the anisotropy extracted from reflectance measurements on GaP thin films on Si(001) [O. Supplie et al., Phys. Rev. B 86, 035308 (2012)PRBMDO1098-012110.1103/PhysRevB.86.035308]. Optical excitations from two states localized in several Si layers adjacent to the interface result in the observed anisotropy of the interface. The calculations show excellent agreement with experiment only for a gapped interface with a P layer in contact with Si and show that a combination of theory and experiment can reveal localized electronic states and the atomic structure at buried interfaces.

The response of earthworms (Eisenia fetida) and soil microbes to the crumb rubber material used in artificial turf fields.

Municipalities have been replacing grass fields with artificial turf, which uses crumb rubber infill made from recycled tires. Crumb rubber contains hydrocarbons, organic compounds, and heavy metals. Water runoff from crumb rubber fields contains heavy metals. These components can damage the environment. We contaminated topsoil with new crumb rubber and measured its impact on earthworms and soil microbes. Specifically, we compared soil microbe activity and earthworm health, survivorship, and longevity in heat and light stress under two soil regimes: clean topsoil and clean topsoil contaminated with crumb rubber. We then characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published New York soil background levels and to levels set by the New York State Department of Environmental Conservation (DEC) as remediation goals. We found that: 1) contaminated soil did not inhibit microbial respiration rates, 2) earthworm survivorship was not impacted by exposure to contaminated soil, 3) earthworms' ability to cope with heat and light stress remained unchanged after living in contaminated soil, but 4) earthworms living in contaminated soil gained 14% less body weight than did earthworms living in uncontaminated soil. We also found that, with the exception of zinc, heavy metals in our contaminated soil did not exceed the background levels found throughout New York State or the remediation targets set by the DEC.

Reflectance anisotropy of the anatase Tio2(0 0 1)-(4 × 1) surface.

The dielectric functions of bulk anatase TiO(2) and its (4 × 1) reconstructed (0 0 1) surface were calculated using a hybrid density functional theory method. The bulk dielectric function is compared to data obtained from synchrotron radiation reflectivity measurements in the energy range 0-20 eV and to dielectric functions from two Bethe-Salpeter calculations. There is agreement between predictions of the two theoretical methods, except at the absorption threshold, where there is some shift of spectral weight to lower energy in the Bethe-Salpeter calculations. All features observed in the dielectric function derived from synchrotron reflectivity data are reproduced in calculations. There are some differences in relative peak intensities for dielectric functions derived from experiment and theory. A dispersionless surface state is found which is localised on the topmost oxygen ion in the reconstructed surface. The reflectance anisotropy spectrum of the TiO(2)(0 0 1)-(4 × 1) surface shows strong features in the energy range to 12 eV but does not show any features caused by sub-bandgap surface state transitions.

Transition levels of defects in ZnO: total energy and Janak's theorem methods.

Transition levels of defects are commonly calculated using either methods based on total energies of defects in relevant charge states or energy band single particle eigenvalues. The former method requires calculation of total energies of charged, perfect bulk supercells, as well as charged defect supercells, to obtain defect formation energies for various charge states. The latter method depends on Janak's theorem to obtain differences in defect formation energies for various charge states. Transition levels of V(Zn), V(O), and V(ZnO) vacancy defects in ZnO are calculated using both methods. The mean absolute deviation in transition level calculated using either method is 0.3 eV. Relative computational costs and accuracies of the methods are discussed.