Spin-Dependent WIMP Limits from a Bubble Chamber Behnke, E; Collar, J.I; Cooper, P.S ...
Science (American Association for the Advancement of Science),
02/2008, Letnik:
319, Številka:
5865
Journal Article
Recenzirano
Odprti dostop
Bubble chambers were the dominant technology used for particle detection in accelerator experiments for several decades, eventually falling into disuse with the advent of other techniques. We report ...here on a new application for these devices. We operated an ultraclean, room-temperature bubble chamber containing 1.5 kilograms of superheated CF₃I, a target maximally sensitive to spin-dependent and -independent weakly interacting massive particle (WIMP) couplings. An extreme intrinsic insensitivity to the backgrounds that commonly limit direct searches for dark matter was measured in this device under operating conditions leading to the detection of low-energy nuclear recoils like those expected from WIMPs. Improved limits on the spin-dependent WIMP-proton scattering cross section were extracted during our experiments, excluding this type of coupling as a possible explanation for a recent claim of particle dark-matter detection.
The system of a trapped ion translationally excited by a blue-detuned near-resonant laser, sometimes described as an instance of a phonon laser, has recently received attention as interesting in its ...own right and for its application to non-destructive readout of internal states of non-fluorescing ions. Previous theoretical work has been limited to cases of two-level ions. Here, we perform simulations to study the dynamics of a phonon laser involving the Λ-type ion, in which coherent population trapping (CPT) effects lead to different behavior than in the previously studied cases. We explore optimization of the laser parameters to maximize amplification gain for initially seeded motion and consider the related signal-to-noise ratios for internal state readout. We find that good Doppler amplification and state readout performance can be obtained even when operating quite near the CPT dip.
Mandible fractures account for 36 to 70 percent of all facial fractures. Despite their high prevalence, the literature lacks a comprehensive review of demographics, fracture patterns, timing of ...management, antibiotic selection, and outcomes, particularly when evaluating pediatric versus adult patients. The authors aim to determine the complication and infection rates after surgical treatment of mandibular fractures and the bacterial isolates and antibiotic sensitivities from mandible infections after open reduction and internal fixation at their institution.
Data were collected retrospectively for all mandible fractures treated at the authors' institution between 2003 and 2013. Patients were divided into pediatric (younger than 16 years) and adult (16 years or older) subgroups. Demographics, fracture location, fracture cause, comorbidities, antibiotic choice, and subsequent complications and infections were analyzed. Data were evaluated using appropriate statistical tests for each variable.
Three hundred ninety-five patients were evaluated. Demographics and fracture cause were similar to those reported in current literature. Of the 56 pediatric patients, complications occurred in 5.6 percent. Time from injury to operative intervention did not affect outcome. The complication rate was 17.5 percent and the infection rate was 9.4 percent in the adult subgroup. Time from injury to operative intervention, sex, and edentulism were not significant predictors of complication or infection. Tobacco use, number of fractures, number of fractures fixated, and surgical approach were predictors of complication and infection. Perioperative ampicillin-sulbactam had a significantly lower risk of infection.
Certain demographic and operative factors lead to significantly higher risks of complications after surgical management of mandibular fractures. Ampicillin-sulbactam provides effective antibiotic prophylaxis. Risk factor modification may improve outcomes.
Risk, IV.
Abstract Objectives We aim to describe our experiences and identify patients who may benefit from referral to a peripheral nerve surgeon for removal of contraceptive subdermal implants in which ...neurovascular injury may occur, and describe a treatment pathway for optimal care. Study design We reviewed the charts of 22 patients who were referred to the Division of Family Planning for difficult removal of etonogestrel contraceptive implants between January 1, 2014, and April, 1 2016. Of these, five were referred to a peripheral nerve surgeon due to pain or location of the implant. We evaluated and described these cases and, from our findings, developed recommendations for care in a multidisciplinary team approach. Results Two patients reported pain, including one with four previous failed removal attempts. In the two patients with pain, the implants were adherent to a sensory nerve. In another, the implant was within the biceps muscle and difficult to locate. In all cases, ultrasound imaging, general anesthesia and a wide exposure allowed for safe removal and good outcomes. Our multidisciplinary care approach has elucidated important referral and technical considerations that improve patient care and safety. Conclusion When necessary, multidisciplinary care with a Family Planning expert and possibly a peripheral nerve surgeon may be beneficial in safely removing etonogestrel contraceptive implants that would be difficult or risky to remove in an ambulatory setting.
The indistinguishability of identical quantum particles can lead to quantum
interferences that profoundly affect their scattering. If
two particles collide and scatter, the process that results in ...the detection
of the first particle in one direction and the second particle in another
direction interferes quantum mechanically with the physically indistinguishable
process where the roles of the particles are reversed. For bosons such as
photons, a constructive interference between probability amplitudes can enhance
the probability, relative to classical expectations, that both are detected
in the same direction - this is known as 'bunching'. But
for fermions such as electrons, a destructive interference should suppress
this probability ('anti-bunching'); this interference is the origin
of the Pauli exclusion principle, which states that two electrons can never
occupy the same state. Although two-particle interferences have been shown
for colliding photons, no similar demonstration for electrons
exists. Here we report the realization of this destructive
quantum interference in the collision of electrons at a beam splitter. In
our experiments, the quantum interference responsible for the Pauli exclusion
principle is manifest as the suppression in electron current noise after collision.
Background
Autologous breast reconstruction offers excellent long term outcomes after mastectomy. However, maintaining adequate postoperative analgesia remains challenging. Use of paravertebral ...blocks (PVBs) reduces postoperative narcotic use and length of stay, and enhanced recovery protocols with mixed analgesia methods are gaining popularity, but few studies have explored the intraoperative effects of these interventions.
Methods
Patients who underwent abdominally based autologous breast reconstruction between 2010 and 2016 were compiled into a retrospective database. We used electronic medical records to determine demographics, as well as perioperative and intraoperative vital signs and narcotic, anxiolytic, crystalloid, colloid, blood product, and vasopressor requirements, and postoperative complications. Results were compared between patients who had a PVB and those who did not and those who had a PVB alone and those who followed our enhanced recovery protocol using standard statistical methods and adjusting for preoperative values.
Results
A total of 170 patients were included in the study. Sixty-six had a PVB, and 104 did not. Of the 66 who had a PVB, 19 followed our enhanced recovery protocol. Patients who did not have a PVB required 171.6 mg of total narcotic medication in the perioperative period, those with a PVB alone required 146.9 mg, and those who followed the ERAS protocol 95.2 mg (
p
= 0.01). There was no difference in intraoperative mean arterial pressure, time with mean arterial pressure <80% of baseline, vasopressor use, or fluid requirement. There was no difference in complication rate.
Conclusions
PVBs and an enhanced recovery protocol reduce the use of narcotic medications in autologous breast reconstruction without impacting intraoperative hemodynamics. Breast reconstruction after mastectomy restores body image and improves health-related quality of life, satisfaction with appearance and physical, psychosocial, and sexual well-being (Donovan et al. in J Clin Oncol 7(7):959–968,
1989
; Eltahir et al. in Plast Reconstr Surg 132(2):201e–209e,
2013
; Jagsi et al. in Ann Surg 261(6):1198–1206,
2015
). For patients pursuing breast reconstruction, there are two major options: prosthetic (tissue expander/implant) or autologous reconstruction. However, while providing exceptional long-term outcomes, postoperative pain and length of hospital stay remains a major challenge preventing more widespread adoption of autologous breast reconstruction (Albornoz et al. in Plast Reconstr Surg 131(1):15–23,
2013
; Gurunluoglu et al. in Ann Plast Surg 70(1):103–110,
2013
; Kulkarni et al. in Plast Reconstr Surg 132(3):534–541,
2013
; Sbitany et al. in Plast Reconstr Surg 124(6):1781–1789,
2009
). Acute postoperative pain contributes to prolonged hospital stays, increased narcotic use, and associated risks of the aforementioned.
Purpose
Tamoxifen therapy is integral in the treatment of patients with hormone receptor-positive breast cancer. However, there is an association between tamoxifen and thromboembolic events. Flap and ...systemic thromboembolic events have devastating consequences in microvascular breast reconstruction. Currently, there are conflicting data on the association between tamoxifen therapy and thromboembolic complications for patients undergoing microvascular breast reconstruction. The objective of this study is to determine if perioperative tamoxifen therapy modifies the risk of complications and thromboembolic events for patients with breast cancer undergoing microvascular breast reconstruction.
Methods
A comprehensive literature search was performed across six databases from January 2003 to February 2016. Pooled estimates and relative risk (RR) were calculated using a random-effects model, confounding was examined with meta-regression, and risk of bias was evaluated. Primary outcomes were thrombotic flap complications and total flap loss. Study quality was assessed using Downs and Black criteria.
Results
Of 95 studies reviewed, 4 studies comprising 1700 patients and 2245 procedures were included for analysis. Compared to non-recipients, patients on tamoxifen were at increased risk of developing thrombotic flap complications (pooled RR 1.5; 95% CI 1.14–1.98) and total flap loss (pooled RR 3.35; 95% CI 0.95–11.91). There was no significant heterogeneity present in either outcome and no evidence of publication bias.
Conclusions
Perioperative tamoxifen therapy may increase the risk of thrombotic flap complications and flap loss for patients with breast cancer undergoing microvascular reconstruction. These findings further the ability of providers to make evidence-based recommendations in the perioperative management of patients with breast cancer.
Persons with multiple sclerosis (PwMS) have been considered at high risk for vaccination and/or acquisition of COVID-19 related to their reduced immune systems and daily regimen of immune suppressing ...therapy. Substantiated and unsubstantiated reports on these unknown circumstances increased anxiety and depression. Low-dose naltrexone (LDN) is a potentially effective off-label therapy shown to be effective at controlling fatigue for several autoimmune disorders including MS. This study utilized a small population of PwMS from central Pennsylvania in order to determine whether LDN therapy altered their perceived anxiety or depression during the early months of COVID-19. Utilizing mailed surveys, self-reported anxiety and depression scores were found to be significantly lower for PwMS who were prescribed LDN either alone or as an adjuvant to a standard disease modifying therapy (DMT) in comparison to those on oral disease-modifying therapies (DMTs). The data suggest that the non-toxic, inexpensive biotherapeutic may be beneficial in lessening anxiety.
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