Effect of plastic coating on the density of plasma formed in Si foil targets irradiated by ultra-high-contrast relativistic laser pulses.

The formation of high energy density matter occurs in inertial confinement fusion, astrophysical, and geophysical systems. In this context, it is important to couple as much energy as possible into a target while maintaining high density. A recent experimental campaign, using buried layer (or "sandwich" type) targets and the ultrahigh laser contrast Vulcan petawatt laser facility, resulted in 500 Mbar pressures in solid density plasmas (which corresponds to about 4.6×10^{7}J/cm^{3} energy density). The densities and temperatures of the generated plasma were measured based on the analysis of x-ray spectral line profiles and relative intensities.

Validity of a low-cost Lichtenstein open inguinal hernia repair simulation model for surgical training.

PURPOSE: Simulation training allows trainees to gain experience in a safe environment. Computer simulation and animal models to practice a Lichtenstein open inguinal hernia repair (LOIHR) are available; however, a low-cost model is not. We constructed an inexpensive model using fabric, felt, and yarn that simulates the anatomy and hazards of the LOIHR. This study examined the fidelity, and perceived usefulness of our developed simulation model by surgical residents and expert surgeons. METHODS: A total of 66 Dutch surgical residents and ten international expert surgeons were included. All participants viewed a video-demonstration of LOIHR on the simulation model and subsequently performed the surgery themselves on the model. Afterward, they assessed the model by rating 13 statements concerning its fidelity (six model, three equipment, and four psychological) and six usefulness statements on a five-point Likert scale. One-sample Wilcoxon signed-rank test was used to compare to the neutral value of 3. RESULTS: The fidelity was assessed as being high by residents [model 4.00 (3.00-4.00), equipment 4.00 (3.00-4.00), psychological 4.00 (3.00-4.00); all p's < 0.001] and by expert surgeons [model 4.00 (3.00-4.00), p = 0.025; equipment 4.00 (3.00-5.00), p < 0.001; psychological 4.00 (3.00-4.00), p = 0.053]. The usefulness was rated high by residents and experts, especially the usefulness for training of residents [residents 4.00 (4.00-5.00), p < 0.001; experts 4.50 (3.75-5.00), p = 0.015]. CONCLUSION: Our developed Lichtenstein open inguinal hernia repair simulation model was assessed by surgical residents and expert surgeons as a model with high fidelity and high potential usefulness, especially for the training of surgical residents.

An optically multiplexed single-shot time-resolved probe of laser-plasma dynamics.

We introduce a new approach to temporally resolve ultrafast micron-scale processes via the use of a multi-channel optical probe. We demonstrate that this technique enables highly precise time-resolved, two-dimensional spatial imaging of intense laser pulse propagation dynamics, plasma formation and laser beam filamentation within a single pulse over four distinct time frames. The design, development and optimization of the optical probe system is presented, as are representative experimental results from the first implementation of the multi-channel probe with a high-power laser pulse interaction with a helium gas jet target.

Surgical trends of groin hernia repairs performed for recurrence in medicare patients.

BACKGROUND: The recurrence rate after groin hernia repair (GHR) has been estimated to be between 1-10% in adult patients. Neither national rates nor trends in recurrence over time have been reliably established for Medicare patients in the USA. MATERIALS: We evaluated patients undergoing GHR (inguinal = IHR; femoral = FHR) from 2011 to 2014 from the Medicare Provider Analysis and Review database. Patients were identified using ICD-9 diagnosis and ICD-9 and CPT procedure codes, stratified both by primary vs. recurrent hernia repair and by sex. One-tailed Cochran-Armitage tests evaluated trends over time and a generalized estimating equation model estimated factors associated with recurrent IHR or FHR. RESULTS: We identified 407,717 patients (87.0%, ≥ 65 years) who underwent an IHR and 11,578 (91.0%, ≥ 65 years) who underwent a FHR. The proportion of IHRs for recurrence decreased statistically from 14.3% in 2011 to 13.9% in 2014 (p < 0.01) in males and was increased, but not statistically so (7.0-7.4%) in females (p = 0.08). The proportion of FHRs for recurrence was decreased, but not statistically so (16.3-14.8%, p = 0.29) in males and increased in females (5.3-6.3%, p = 0.02). On multivariable analysis, males were more than twice as likely as females to undergo recurrent repair (IHR or FHR, both p < 0.01). CONCLUSIONS: Within the Medicare population, recurrence rates after groin hernia repairs were found to be higher than previously reported but have remained clinically stable over time. Establishing and reducing this rate is important for patient outcomes and expectations.

Proportion of femoral hernia repairs performed for recurrence in the United States.

PURPOSE: Recurrence rates after femoral hernia repair (FHR) have not been reliably established in the USA. We sought to determine this trend over time. METHODS: The proportion of primary and recurrent FHRs was determined for patients age ≥ 18 from: ACS-NSQIP (1/2005-12/2014), Premier (1/2010-09/2015), and institutional (1/2005-12/2014) data. Trends were analyzed using a one-tailed Cochran-Armitage test. RESULTS: In the NSQIP database, 6649 patients underwent a FHR. In females, the proportion of FHRs performed for recurrence decreased from 14.0% in 2005 to 6.2% in 2014, p = 0.02. In males, there was no change: 16.7-16.1% 2005-2014 (p = 0.18). The Premier database included 4495 FHRs and our institution 315 FHRs. There was no difference for either gender over time in either data source, all p > 0.05. CONCLUSIONS: The proportion of femoral hernia repairs performed for recurrence in the USA remained relatively constant in males in two large national databases between 2005 and 2015. In females, a decrease was seen in one of the large national databases.

Enhancing titres of therapeutic viral vectors using the transgene repression in vector production (TRiP) system.

A key challenge in the field of therapeutic viral vector/vaccine manufacturing is maximizing production. For most vector platforms, the 'benchmark' vector titres are achieved with inert reporter genes. However, expression of therapeutic transgenes can often adversely affect vector titres due to biological effects on cell metabolism and/or on the vector virion itself. Here, we exemplify the novel 'Transgene Repression In vector Production' (TRiP) system for the production of both RNA- and DNA-based viral vectors. The TRiP system utilizes a translational block of one or more transgenes by employing the bacterial tryptophan RNA-binding attenuation protein (TRAP), which binds its target RNA sequence close to the transgene initiation codon. We report enhancement of titres of lentiviral vectors expressing Cyclo-oxygenase-2 by 600-fold, and adenoviral vectors expressing the pro-apoptotic gene Bax by >150,000-fold. The TRiP system is transgene-independent and will be a particularly useful platform in the clinical development of viral vectors expressing problematic transgenes.

TEP and Lichtenstein anatomy: does simulation accelerate acquisition among interns?

PURPOSE: The anatomy of the inguinal region is notoriously challenging to master. We sought to teach open inguinal hernia (OIH) and totally extraperitoneal (TEP) anatomy with simulation models among general surgery (GS) interns. METHODS: Low-fidelity OIH and TEP models were constructed out of cardboard, plastic bins, fabric, and yarn. GS interns (n = 30) participated in a 3-h hernia session including a pretest, anatomy lecture, simulated OIH and TEP hernia repair, and posttest. Pre- and posttest scores were based on a difficult 30-point exam which included didactic questions (10 points), drawing relevant TEP (10 points), and OIH (10 points) anatomy. Participants were surveyed following the session. RESULTS: Median pretest scores were 13 % (range 0-60 %). Median posttest scores improved to 47 % (range 20-93 %, p < 0.001). Median number of structures drawn in the TEP image improved from 2 (range 0-14) to 11 (range 1-21, p < 0.001). Median number of structures drawn in the OIH image improved from 3 (range 0-15) to 7 (range 1-19, p < 0.001). 67 % (12/18) demonstrated improvement in knowledge of abdominal wall layers. 23 % (7/30) knew the triangles of pain/doom on the pretest vs. 77 % (23/30) on the posttest. Mean Likert scores favored session enjoyability (4.5), not a waste of training time (4.4), and improved understanding of OIH and TEP anatomy (4.4, 4.2). CONCLUSIONS: Low-fidelity simulators can be used to teach and assess knowledge of TEP and OIH anatomy. While enjoyable and useful, one 3-h session does not create master hernia surgeons or expert anatomists out of novice trainees.

Relationship between body mass index and the incidence of inguinal hernia repairs: a population-based study in Olmsted County, MN.

PURPOSE: The relationship between body mass index (BMI) and the risk of inguinal hernia development is unclear. To explore the relationship, we determined whether the incidence of inguinal hernia repairs (IHR) varied across patients with different BMI categories. STUDY DESIGN: A population-based incidence study was undertaken. We reviewed all IHR performed on adult residents of Olmsted County, MN from 2004 to 2008. Cases were ascertained through the Rochester Epidemiology Project, a records-linkage system with more than 97% population coverage. RESULTS: During the study period, a total of 1,168 IHR were performed on 879 men and 107 women. The median BMI of the cohort was 26.7 kg/m2 (range 14.9-58.1, interquartile range 23.9-28.9). Incidence rates varied significantly as a function of BMI (p<0.001). Rates were highest among men who were either normal weight or overweight (419.8 and 421.1 per 100,000 person-years for BMI<25 and BMI 25-29.9, respectively), and lowest for obese and morbidly obese men (273.5 and 99.4 per 100,000 person-years for BMI 30-34.9 and BMI C 35, respectively). Findings were similar across all age categories and in patients who had an IHR that was initial or recurrent, direct or indirect, and unilateral or bilateral. CONCLUSIONS: The incidence of IHR decreased as BMI increased. Obese and morbidly obese patients had a lower incidence of IHR than those who were normal weight or overweight. The causal mechanisms leading to such a relationship are unclear and warrant further study.

Hot-spot mix in ignition-scale inertial confinement fusion targets.

Mixing of plastic ablator material, doped with Cu and Ge dopants, deep into the hot spot of ignition-scale inertial confinement fusion implosions by hydrodynamic instabilities is diagnosed with x-ray spectroscopy on the National Ignition Facility. The amount of hot-spot mix mass is determined from the absolute brightness of the emergent Cu and Ge K-shell emission. The Cu and Ge dopants placed at different radial locations in the plastic ablator show the ablation-front hydrodynamic instability is primarily responsible for hot-spot mix. Low neutron yields and hot-spot mix mass between 34(-13,+50) ng and 4000(-2970,+17 160) ng are observed.

Precision shock tuning on the national ignition facility.

Ignition implosions on the National Ignition Facility [J. D. Lindl et al., Phys. Plasmas 11, 339 (2004)] are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal density (ρR) to sustain a self-propagating burn wave required for fusion power gain greater than unity. These implosions are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision to keep the fuel entropy and adiabat low and ρR high. The first series of precision tuning experiments on the National Ignition Facility, which use optical diagnostics to directly measure the strength and timing of all four shocks inside a hohlraum-driven, cryogenic liquid-deuterium-filled capsule interior have now been performed. The results of these experiments are presented demonstrating a significant decrease in adiabat over previously untuned implosions. The impact of the improved shock timing is confirmed in related deuterium-tritium layered capsule implosions, which show the highest fuel compression (ρR~1.0 g/cm(2)) measured to date, exceeding the previous record [V. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010)] by more than a factor of 3. The experiments also clearly reveal an issue with the 4th shock velocity, which is observed to be 20% slower than predictions from numerical simulation.

Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions.

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 µm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).

Trends in emergent inguinal hernia surgery in Olmsted County, MN: a population-based study.

BACKGROUND: Evidence suggests that watchful waiting of inguinal hernias (IH) is safe because the risk of acute strangulation requiring an emergent repair is low. However, population-based incidence rates are lacking, and it is unknown whether the incidence of emergent inguinal hernia repairs (IHR) has changed over time. STUDY DESIGN: A retrospective review of all IHR performed on adult residents of Olmsted County, Minnesota from 1989 to 2008 was performed using the Rochester epidemiology project, a record-linkage system that covers more than 97 % of the population (2010 US Census = 146,466). Incidence rates/100,000 person-years were calculated, and trends over time were evaluated using Poisson regression. RESULTS: A total of 4,026 IHR were performed on 3,599 patients; 136 repairs (3.8 %) were emergent. Of these, 19 patients (14 %) had bowel resection and three (2 %) died within 30 days of the repair. Rates/100,000 person-years yielded an overall incidence of 7.6 for emergent IHR and 200.0 for elective IHR. Emergent IHR rates increased with age. Overall emergent IHR rates declined from 18.2 to 12.4 in men and from 6.4 to 2.4 in women from 1989 to 2008 (p > 0.05). Older age, obesity, a high ASA risk score, a femoral and/or a recurrent hernia were more likely to be associated with an emergent IHR (all p ≤ 0.05). CONCLUSION: The incidence of emergent IHR is low. This risk has decreased over the past 20 years. However, patients who are either ≥70 years old, obese, with a high ASA score, or with a femoral or recurrent hernias are more likely to require an emergent IHR and could benefit from elective operative intervention if deemed adequate surgical candidates.

Obturator hernia: the Mayo Clinic experience.

BACKGROUND: Obturator herniae (OH) are rare, with nonspecific signs and symptoms, and diagnosis is usually delayed until laparotomy. The added benefit of preoperative diagnosis with computed tomography (CT) remains unclear. METHODS: We reviewed the clinical characteristics and outcomes of OH repairs performed at our institution over a 58-year period. Outcomes were compared between patients who did or did not have a preoperative CT. RESULTS: Between 1950 and 2008, 30 patients (median age 82 years, 29 women) underwent OH repair. The most common presenting signs and symptoms were bowel obstruction (63%), abdominal/groin pain (57%), and a palpable lump (10%). The pathognomonic Howship-Romberg sign was present in 11 patients (37%). The diagnosis was made preoperatively in nine patients: clinically in one (3%) and with CT in eight (27%). Nineteen patients (63%) presented emergently. Primary and prosthetic repair were performed in 23 (77%) and seven (23%) patients, respectively. Small-bowel resection was performed in 14 patients (47%). Perioperative morbidity (30%) and mortality (10%) rates were high. Patients with a preoperative CT were less likely to develop a postoperative complication of any type [odds ratio (OR) 0.8, P = 0.04]; however, time to operation, length of stay, need for bowel resection, and mortality rate did not differ (P = NS). No recurrences were detected at a median follow-up of 2 years (range 0-55). CONCLUSION: Although CT imaging provides an excellent means of preoperative diagnosis, suggestive signs and symptoms in a "skinny old lady" should prompt immediate operative intervention without delay.

Contralateral metachronous inguinal hernias in adults: role for prophylaxis during the TEP repair.

PURPOSE: Contralateral exploration during laparoscopic totally extraperitoneal (TEP) inguinal herniorrhaphy allows for the repair of incidentally found hernias. Nonetheless, some patients with a negative contralateral exploration subsequently develop a symptomatic hernia on that side. We pondered the incidence of contralateral metachronous hernia development and whether prophylactic "repair" in these circumstances would be beneficial. METHODS: A retrospective analysis of patients who underwent laparoscopic TEP exploration at our institution was performed. Demographic, operative and follow-up information was obtained through medical record review, physical examination and telephone/mailed survey. RESULTS: From 1995 to 2009, a total of 1,479 inguinal herniorrhaphies on 976 patients were performed by a single staff surgeon. Bilateral exploration was completed in 923 (95%) of these patients, of whom bilateral repair was performed on 503 (55%). The study cohort comprises the 409 (42%) patients having a unilateral repair with a negative contralateral exploration and no previous contralateral hernia repair (n = 11). With a median follow-up of 5.9 years (range 0-14), 33 (8.1%) hernias developed on the previously "healthy" side, yielding incidence rates at 1, 5 and 10 years of 1.6, 5.9 and 11.8%, respectively. The median time to hernia development was 3.7 years (range 0.1-12.4). Of the 30 inguinal hernias that have been repaired, 25 (83%), 3 (10%) and 2 (7%) were of indirect, direct and pantaloon types, respectively. CONCLUSIONS: When considering prophylactic repair during TEP explorations, a yearly risk of 1.2% of developing a contralateral hernia after negative exploration needs to be balanced against the low but potential risk of groin pain following prophylactic repair.

Placental amino acid transport and placental leptin resistance in pregnancies complicated by maternal obesity.

UNLABELLED: HYPOTHESIS AND STUDY OBJECTIVES: We hypothesized that maternal obesity is associated with increased placental amino acid transport and hyperleptinemia. Our objectives were to study placental amino acid transport and the effect of leptin on placental amino acid transport in vitro in the setting of maternal obesity. MATERIALS AND METHODS: Seven lean, BMI at entry 22.4, and seven obese, BMI at entry 31.5 (p < 0.001), pregnant women were studied at 39 weeks. We measured baseline and leptin-stimulated placental system A sodium-dependent neutral amino acid transporter (SNAT) activity, placental immunoreactive protein expression of SNAT, leptin and leptin receptor, and maternal and fetal plasma leptin concentrations, with significance set at p

Feto-placental adaptations to maternal obesity in the baboon.

Maternal obesity is present in 20-34% of pregnant women and has been associated with both intrauterine growth restriction and large-for-gestational age fetuses. While fetal and placental functions have been extensively studied in the baboon, no data are available on the effect of maternal obesity on placental structure and function in this species. We hypothesize that maternal obesity in the baboon is associated with a maternal inflammatory state and induces structural and functional changes in the placenta. The major findings of this study were: 1) decreased placental syncytiotrophoblast amplification factor, intact syncytiotrophoblast endoplasmic reticulum structure and decreased system A placental amino acid transport in obese animals; 2) fetal serum amino acid composition and mononuclear cells (PBMC) transcriptome were different in fetuses from obese compared with non-obese animals; and 3) maternal obesity in humans and baboons is similar in regard to increased placental and adipose tissue macrophage infiltration, increased CD14 expression in maternal PBMC and maternal hyperleptinemia. In summary, these data demonstrate that in obese baboons in the absence of increased fetal weight, placental and fetal phenotype are consistent with those described for large-for-gestational age human fetuses.

Metastatic malignant melanoma.

Metastatic malignant melanoma is an incurable malignancy with extremely poor prognosis. Patients bearing this diagnosis face a median survival time of approximately 9 months with a probability of surviving 5 years after initial presentation at less than 5%. This is contrasted by the curative nature of surgical resection of early melanoma detected in the skin. To date, no systemic therapy has consistently and predictably impacted the overall survival of patients with metastatic melanoma. However, in recent years, a resurgence of innovative diagnostic and therapeutic developments have broadened our understanding of the natural history of melanoma and identified rational therapeutic targets/strategies that seem poised to significantly change the clinical outcomes in these patients. Herein we review the state-of-the-art in metastatic melanoma diagnostics and therapeutics with particular emphasis on multi-disciplinary clinical management.

Adverse-event-reporting practices by US hospitals: results of a national survey.

CONTEXT: Little is known about hospitals' adverse-event-reporting systems, or how they use reported data to improve practices. This information is needed to assess effects of national patient-safety initiatives, including implementation of the Patient Safety and Quality Improvement Act of 2005 (PSQIA). This survey generated baseline information on the characteristics of hospital adverse-event-reporting systems and processes, for use in assessing progress in improvements to reporting. METHODS: The Adverse Event Reporting Survey, developed by Westat, was administered in September 2005 through January 2006, using a mixed-mode (mail/telephone) survey with a stratified random sample of 2050 non-federal US hospitals. Risk managers were the respondents. An 81% response rate was obtained, for a sample of 1652 completed surveys. RESULTS: Virtually all hospitals reported they have centralised adverse-event-reporting systems, although characteristics varied. Scores on four performance indexes suggest that only 32% of hospitals have established environments that support reporting, only 13% have broad staff involvement in reporting adverse events, and 20-21% fully distribute and consider summary reports on identified events. Because survey responses are self-reported by risk managers, these may be optimistic assessments of hospital performance. CONCLUSIONS: Survey findings document the current status of hospital adverse-event-reporting systems and point to needed improvements in reporting processes. PSQIA liability protections for hospitals reporting data to patient-safety organisations should also help stimulate improvements in hospitals' internal reporting processes. Other mechanisms that encourage hospitals to strengthen their reporting systems, for example, strong patient-safety programmes, also would be useful.

Consequences of endoscopic inguinal hernioplasty with mesh on subsequent open radical prostatectomy.

AIM: To determine the effect of prior endoscopic hernia repair with prosthetic mesh on subsequent open radical prostatectomy. METHODS: A retrospective study from 1990 to 2004 identified nine patients with preperitoneal mesh placement followed by open radical prostatectomy. Case controls (n = 26) were matched for age, type of operation, year of surgery and pathologic stage of prostatic adenocarcinoma. Outcome variables of operating time, number of pelvic lymph nodes excised, duration of hospital stay, duration of urinary catheterization, recurrence rates, and incidence of complications were compared. Data analysis was performed using Wilcoxon's rank sums test. RESULTS: Intraoperatively, subjective difficulty in dissection was documented in all cases by the performing urologist. Duration of hospital stay was significantly increased by 1.3 days (p < 0.05), as compared to the control group. However, no statistically significant increase in mean operating time (173 vs. 172 min, p = 0.925), number of lymph nodes sampled (4.4 vs. 6.6, p = 0.147), duration of urinary catheterization (22 vs. 19 days, p = 0.925), oncologic recurrence (11 vs. 11% at 6.1 and 4.8 years follow-up), or complications was found. CONCLUSIONS: Prior TEP/TAPP did not increase the morbidity or mortality of subsequent prostate surgery. Despite some subjective operative difficulty, open prostatectomy was safe and feasible in all cases with a comparable oncologic outcome. Mesh-associated inflammation may preclude adequate nodal sampling. While endoscopic hernia repair remains an excellent option to fix unilateral, bilateral, and recurrent herniae, consideration of future prostate surgery is important. Inserting less "inflammatory" mesh or using an open, anterior approach may be prudent in some men at high risk for needing subsequent prostate surgery.