Lynx x-ray microcalorimeter.

Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be a flagship mission. One of Lynx's three instruments is an imaging spectrometer called the Lynx x-ray microcalorimeter (LXM), an x-ray microcalorimeter behind an x-ray optic with an angular resolution of 0.5 arc sec and ∼2 m2 of area at 1 keV. The LXM will provide unparalleled diagnostics of distant extended structures and, in particular, will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the baseline design of LXM and some parallel approaches for some of the key technologies. The baseline sensor technology uses transition-edge sensors, but we also consider an alternative approach using metallic magnetic calorimeters. We discuss the requirements for the instrument, the pixel layout, and the baseline readout design, which uses microwave superconducting quantum interference devices and high-electron mobility transistor amplifiers and the cryogenic cooling requirements and strategy for meeting these requirements. For each of these technologies, we discuss the current technology readiness level and our strategy for advancing them to be ready for flight. We also describe the current system design, including the block diagram, and our estimate for the mass, power, and data rate of the instrument.

The Beta 2 Adrenergic Receptor Antagonist Timolol Improves Healing of Combined Burn and Radiation Wounds.

In a scenario involving a nuclear detonation during war or a terrorist attack, acute radiation exposure combined with thermal and blast effects results in severe skin injury. Although the cutaneous injury in such a scenario may not be lethal, it may lead to inflammation, delayed wound healing and loss of the skin barrier, resulting in an increased risk of infection. In this study, we tested the potential use of timolol, a beta-adrenergic receptor antagonist, to improve epidermal wound closure after combined burn and radiation injury using an ex vivo human skin culture model. Daily application of 10 µ M timolol after combined injury (burn and 10 Gy ex vivo irradiation) increased wound epithelialization by 5-20%. In addition, exposure to 10 Gy significantly suppressed epidermal keratinocyte proliferation by 46% at 48 h postirradiation. Similar to what has been observed in a thermal burn injury, the enzyme phenylethanolamine N-methyltransferase (PNMT), which generates epinephrine, was elevated in the combined thermal burn and radiation wounds. This likely resulted in elevated tissue levels of this catecholamine, which has been shown to delay healing. Thus, with the addition of timolol to the wound to block the binding of locally generated epinephrine to the beta-adrenergic receptor, healing is improved. This work suggests that by antagonizing local epinephrine action within the wound, a beta-adrenergic receptor antagonist such as timolol may be a useful adjunctive treatment to improve healing in the combined burn and radiation injury.

The Plastic Surgeon as Employee: A Pilot Survey of the California Society of Plastic Surgeons.

INTRODUCTION: Plastic surgeons endure years of training yet remain poorly equipped to negotiate first employment contracts. Our aims were to evaluate typical plastic surgeon employment contracts and assess contract comprehensiveness. We sought elements that should be included to better preserve varied interests. METHODS: A brief, anonymous, e-mailed survey was sent to California Society of Plastic Surgeons members and responses collected over 2 months. We collected information such as years in practice, geographic area, types of practices and number of surgeons within them, and legal standing of partnerships. We asked whether respondents sought legal assistance and specific elements were elaborated. We asked how content they were with their contracts while allowing commentary. RESULTS: Our survey generated 113 responses. 50.0% of respondents reported being in practice for at least 20 years; 2.68% had been in practice for up to 5 years. 62.5% reported being in private practice and 27.7% reported being in academia. In-state geographic distribution of respondents accounted for 85.6%, whereas 14.4% reported practicing out-of-state.Practice size was diverse, with 41.4% of respondents having worked in a group practice of 3 or more, 27.9% in partnership, and 23.4% in solo practice. For partnerships, 29.9% had made formal legal arrangements, whereas 20.6% had made informal arrangements. 74.5% of respondents did not seek legal assistance.Malpractice coverage varied from 51.6% with claims-made, to 21.7% with tail, to 33.0% with no coverage at all. 63.9% reported having no group disability policy. 26.4% reported annual income of less than US $100,000; 49.1% reported US $101,000 to US $200,000; 17.9% reported US $201,000 to US $300,000; 6.60% reported greater than US $300,000. Using a 5-point scale, 7.69% of respondents reported being "extremely dissatisfied" with their first employment contracts (score of 1), whereas 24.0% were "perfectly happy" (5).Eighty-two respondents offered advice. Common themes included seeking legal counsel; considering eventual solo practice; planning long-term; seeking mentorship; and cautioning against third party interests. CONCLUSIONS: New plastic surgeons will find themselves employed by institutions. Seeking attorneys familiar with the profession is advisable. Lack of awareness regarding malpractice options and disability coverage are 2 areas of concern. We reveal critical contract elements that surgeons should negotiate to ensure smooth transition to practice.

Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction without Microsurgery Fellowship Training.

BACKGROUND: Deep inferior epigastric artery perforator (DIEP) flap breast reconstruction requires complex microsurgical skills. Herein, we examine whether DIEP flap breast reconstruction can be performed safely without microsurgical fellowship training. METHODS: A total of 28 patients and 34 DIEP flaps were included in the study. We reviewed the medical records of patients for donor site and flap-related complications and analyzed the correlation between the complications and preoperative risk factors. We also performed a literature review to compare complication rates in our series with the literature. RESULTS: We observed total flap necrosis in 1 patient (2.9%), partial flap necrosis in 5 patients (14.7%), infection in 1 patient (2.9%), hematoma/seroma in 3 patients (8.8%), donor site complications in 5 patients (18.5%), venous occlusion in 4 patients (11.7%), and arterial occlusion in 1 patient (2.9%). We did not observe any correlation between complications and preoperative risk factors. Literature review yielded 18 papers that met our inclusion criteria. Partial flap necrosis rate was significantly higher in our series compared with literature (14.7% vs 1.6%, P = 0.003). Venous complication rate was marginally higher in our series compared with literature (11.7% vs 3.3%, P = 0.057). However, total flap loss rate in our series was comparable with the literature (2.9% vs 2.2%, P = 0.759). CONCLUSION: With proper training during plastic surgery residency, DIEP flap can be performed with acceptable morbidity.

Angular and polarization response of multimode sensors with resistive-grid absorbers.

High-sensitivity receiver systems with near-ideal polarization sensitivity are highly desirable for development of millimeter and submillimeter radio astronomy. Multimoded bolometers provide a unique solution to achieve such sensitivity, for which hundreds of single-mode sensors would otherwise be required. The primary concern in employing such multimoded sensors for polarimetery is the control of the polarization systematics. In this work, we examine the angular- and polarization-dependent absorption pattern of a thin resistive grid or membrane, which models an absorber used for a multimoded bolometer. The result shows that a freestanding thin resistive absorber with a surface resistivity of η/2, where η is the impedance of free space, attains a beam pattern with equal E- and H-plane responses, leading to zero cross-polarization. For a resistive-grid absorber, the condition is met when a pair of grids is positioned orthogonal to each other and both have a resistivity of η/2. When a reflective backshort termination is employed to improve absorption efficiency, the cross-polar level can be suppressed below -30 dB if acceptance angle of the sensor is limited to ≲60°. The small cross-polar systematics have even-parity patterns and do not contaminate the measurements of odd-parity polarization patterns, for which many of the recent instruments for cosmic microwave background are designed. Underlying symmetry that suppresses these cross-polar systematics is discussed in detail. The estimates and formalism provided in this work offer key tools in the design consideration of the instruments using the multimoded polarimeters.

Micro-Spec: an ultracompact, high-sensitivity spectrometer for far-infrared and submillimeter astronomy.

High-performance, integrated spectrometers operating in the far-infrared and submillimeter ranges promise to be powerful tools for the exploration of the epochs of reionization and initial galaxy formation. These devices, using high-efficiency superconducting transmission lines, can achieve the performance of a meter-scale grating spectrometer in an instrument implemented on a 4 inch silicon wafer. Such a device, when combined with a cryogenic telescope in space, provides an enabling capability for studies of the early universe. Here, the optical design process for Micro-Spec (µ-Spec) is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the stigmatization and minimization of the light path function in this bounded region, which results in an optimized geometrical configuration. A point design with an efficiency of ~90% has been developed for initial demonstration and can serve as the basis for future instruments. Design variations on this implementation are also discussed, which can lead to lower efficiencies due to diffractive losses in the multimode region.

Impact of bisphosphonate drug burden in alveolar bone during orthodontic tooth movement in a rat model: a pilot study.

INTRODUCTION: The aim of this pilot study was to investigate the effect of long-term bisphosphonate drug use (bone burden) on orthodontic tooth movement in a rat model. METHODS: Sprague Dawley rats were used for orthodontic protraction of the maxillary first molars with nickel-titanium coil springs and temporary anchorage devices as anchorage. Four groups of 5 rats each were included in the study; the first 2 groups were dosed with alendronate or a vehicle during concurrent orthodontic tooth movement. The third and fourth groups were pretreated for 3 months with alendronate or vehicle injections, and bisphosphonate drug treatment was discontinued before orthodontic tooth movement. Tooth movement measurements were obtained at 0, 4, and 8 weeks using high-resolution in-vivo microcomputed tomography, and the tissues were analyzed with histology and dynamic labeling of bone turnover. RESULTS: Appreciable tooth movement was achieved during the 8-week duration of this study with nickel-titanium coil springs and temporary anchorage devices. Both bisphosphonate treatment groups exhibited reduced tooth movement compared with the vehicle-dosed controls with a tendency toward more severe reduction in the bisphosphonate predosed group. Concurrent dosing of the bisphosphonate drug resulted in 56% and 65% reductions in tooth protraction at the 4-week and 8-week times, respectively. The impact of bisphosphonate bone burden in retarding tooth movement was even greater, with 77% and 86% reductions in tooth movement at 4 and 8 weeks, respectively. CONCLUSIONS: In this study, we used a robust rat model of orthodontic tooth movement with temporary anchorage devices. It has provided evidence that the bone burden of previous bisphosphonate use will significantly inhibit orthodontic tooth movement.

Prevention of earlobe deformity in face-lifting.

"Pixie-ear" deformity is a postrhytidectomy sequela in which the ear lobe is pulled inferiorly. This deformity may be attributed to excessive skin excision inferior to the earlobe, direct suturing of the facial flap to lobule skin, or excessive scarring. When there is increased tension on the earlobe, the otobasion inferius (cephalic attachment point of lobe) migrates from a posterior cephalic position to an anterior caudal position. The authors present an operative technique to prevent pixie-ear deformity and optimize earlobe position in face-lifting.

Transcriptional response of ex vivo human skin to ionizing radiation: comparison between low- and high-dose effects.

Although human exposure to low-dose ionizing radiation can occur through a variety of sources, including natural, medical, occupational and accidental, the true risks of low-dose ionizing radiation are still poorly understood in humans. Here, the global transcriptional responses of human skin after ex vivo exposure to low (0.05 Gy) and high (5 Gy) doses of X rays and of time in culture (0 Gy) at 0, 2, 8 and 30 h postirradiation were analyzed and compared. Responses to low and high doses differed quantitatively and qualitatively. Differentially expressed genes fell into three groups: (1) unique genes defined as responsive to either 0.05 or 5 Gy but not both and also responsive to time in culture, (2) specific genes defined as responsive to either 0.05 or 5 Gy but not both and not responsive to time in culture, and (3) dose-independent responsive genes. Major differences observed in ex vivo irradiated skin between transcriptional responses to low or high doses were twofold. First, gene expression modulated by 0.05 Gy was transient, while in response to 5 Gy persistence of modified gene expression was observed for a limited number of genes. Second, neither TP53 nor TGFß target genes were modulated after exposure to an acute low dose, suggesting that the TP53-dependent DNA damage response either was not triggered or was triggered only briefly.

Autologous fat grafting for primary breast augmentation: a systematic review.

As the technique of autologous fat grafting is being refined and perfected, its clinical applications are expanding. The use of autologous fat grafting for primary breast augmentation is controversial due to a lack of clarity regarding its safety and efficacy. Most notably, concerns about interference with the detection of breast cancer have been raised, but these have not been clearly addressed in the literature. To help surgeons gain further insight, the authors conducted a systematic review of the literature, carefully comparing technique, clinical outcome, radiologic impact, and complications in all available data on this subject. Although an optimal method of autologous fat grafting for primary breast augmentation is yet to be standardized, further strong evidence-based studies are necessary to confirm the findings of this approach.

Sacramento area breast cancer epidemiology study: use of postmastectomy breast reconstruction along the rural-to-urban continuum.

BACKGROUND: Health care disparities have been documented in rural populations. The authors hypothesized that breast cancer patients in urban counties would have higher rates of postmastectomy breast reconstruction relative to patients in surrounding near-metro and rural counties. METHODS: The authors used the Surveillance, Epidemiology, and End Results database to identify patients diagnosed with breast cancer and treated with mastectomy in the greater Sacramento area between 2000 and 2006. Counties were categorized as urban, near-metro, or rural. Univariate models evaluated the relationship of rural, near-metro, or urban location with use of breast reconstruction by means of the chi-square test. Multivariate logistic regression models controlling for patient, tumor, and treatment-related factors predicted use of breast reconstruction. The likelihood of undergoing breast reconstruction was reported as odds ratios with 95 percent confidence intervals; significance was set at p≤0.05. RESULTS: Complete information was available for 3552 breast cancer patients treated with mastectomy. Of these, 718 (20.2 percent) underwent breast reconstruction. On univariate analysis, differences in the rates of breast reconstruction were noted among urban, near-metro, and rural areas (p<0.001). On multivariate analysis, patients from rural (odds ratio, 0.51; 95 percent confidence interval, 0.28 to 0.93; p<0.03) and near-metro (odds ratio, 0.73; 95 percent confidence interval, 0.59 to 0.89; p=0.002) areas had a decreased likelihood of undergoing breast reconstruction relative to patients from urban areas. CONCLUSIONS: Patients from near-metro and rural areas are less likely to undergo breast reconstruction following mastectomy for breast cancer than their urban counterparts. Differences in use of breast reconstruction detected at a population level should guide future interventions to increase rates of breast reconstruction at the local level.

Distally based sural lesser saphenous neuro-veno-adipo-fascial (NVAF) flap for reconstruction in the foot: lessons learned.

We report nine cases in which the neuro-veno-adipo-fascial (NVAF) flap was used to perform reconstruction of foot wounds over a 7-year period. Complications occurred in five (56%) patients. One patient suffered total loss of the flap and four experienced partial loss of the NVAF flap. Complications are to be expected with the use of the NVAF flap for foot wounds, but in most cases the flap is salvageable. The NVAF flap is an option in foot reconstruction when free tissue transfer is not available, contraindicated due to patient factors or when a prior free flap has failed.

Integrated plastic surgery residency applicant survey: characteristics of successful applicants and feedback about the interview process.

BACKGROUND: Integrated plastic surgery residency training is growing in popularity, bringing new challenges to program directors and applicants. The purpose of this study was to identify characteristics of successful applicants and to obtain feedback from applicants to improve the integrated plastic surgery residency training application and interview process. METHODS: An anonymous survey assessing applicant academic qualifications, number of interviews offered and attended, and opinions about the application and interview process was distributed electronically to the 2006 integrated plastic surgery residency training applicant class. The number of interviews offered was used as an indicator of potential applicant success. RESULTS: A 38 percent survey participation rate (139 of 367) was achieved. United States Medical Licensing Examination Step 1 score correlated with number of interview invitations (p < or = 0.001). Successful Alpha Omega Alpha designation (p < or = 0.001), high class rank (p = 0.034), presence of a plastic surgery residency program at the participant's school (p = 0.026), and authorship of one or more publications (p < or = 0.001) were associated with receiving greater number of interview invitations. Geographic location was an important consideration for applicants when applying to and ranking programs. Applicants desired interviews on weekdays and geographic coordination of interviews. CONCLUSIONS: Integrated plastic surgery residency training is highly competitive, with the number of interview invitations correlating with academic performance and, to a lesser extent, research. Applicant feedback from this survey can be used to improve the application and interview process.