Jets and energy flow in photon-proton collisions at HERA

Properties of the hadronic final state in photoproduction events with large transverse energy are studied at the electron-proton collider HERA. Distributions of the transverse energy, jets and underlying event energy are compared to \overline{p}p data and QCD calculations. The comparisons show that the \gamma p events can be consistently described by QCD models including -- in addition to the primary hard scattering process -- interactions between the two beam remnants. The differential jet cross sections d\sigma/dE_T^{jet} and d\sigma/d\eta^{jet} are measured

Разработка интерактивной моделирующей системы технологии низкотемпературной сепарации газа

We present a study of J ψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The J ψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → J ψ X) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ W γp ≤ 180 GeV and Q 2 ≲ 4 GeV 2 . Using the flux of quasi-real photons with Q 2 ≲ 4 GeV 2 , a total production cross section of σ ( γp → J / ψX ) = (56±13±14) nb is derived at an average W γp =90 GeV. The distribution of the squared momentum transfer t from the proton to the J ψ can be fitted using an exponential exp(− b ∥ t ∥) below a ∥ t ∥ of 0.75 GeV 2 yielding a slope parameter of b = (4.7±1.9) GeV −2

α1-Adrenergic Responsiveness in Human Skeletal Muscle Feed Arteries: The Impact of Reducing Extracellular PH

Graded exercise results not only in the modulation of adrenergic mediated smooth muscle tone and a preferential increase in blood flow to the active skeletal muscle termed \u27functional sympatholysis\u27, but is also paralleled by metabolically induced reductions in pH. We therefore sought to determine whether pH attenuates α(1)-adrenergic receptor sensitivity in human feed arteries. Feed arteries (560 ± 31 μm i.d.) were harvested from 24 humans (55 ± 4 years old) and studied using the isometric tension technique. Vessel function was assessed using KCl, phenylephrine (PE), ACh and sodium nitroprusside (SNP) concentration-response curves to characterize non-receptor-mediated and receptor-mediated vasocontraction, as well as endothelium-dependent and -independent vasorelaxation, respectively. All concentration-response curves were obtained from (originally contiguous) vessel rings in separate baths with a pH of 7.4, 7.1, 6.8 or 6.5. Reduction of the pH, via HCl, reduced maximal PE-induced vasocontraction (pH 7.4 = 85 ± 19, pH 7.1 = 57 ± 16, pH 6.8 = 34 ± 15 and pH 6.5 = 16 ± 5% KCl(max)), which was partly due to reduced smooth muscle function, as assessed by KCl (pH 7.4 = 88 ± 13, pH 7.1 = 67 ± 8, pH 6.8 = 67 ± 9 and pH 6.5 = 58 ± 8% KCl(max)). Graded acidosis had no effect on maximal vasorelaxation. In summary, these data reveal that reductions in extracellular pH attenuate α(1)-mediated vasocontraction, which is partly explained by reduced smooth muscle function, although vasorelaxation in response to ACh and SNP remained intact. These findings support the concept that local acidosis is likely to contribute to functional sympatholysis and exercise hyperaemia by opposing sympathetically mediated vasoconstriction while not impacting vasodilatation

Human Skeletal Muscle Feed Arteries: Evidence of Regulatory Potential

AIM: Recently, it has been recognized that human skeletal muscle feed arteries can be harvested during exploratory surgery for melanoma. This approach provides vessels for in vitro study from a wide spectrum of relatively healthy humans. Although, the regulatory role of skeletal muscle feed arteries in rodent models has been documented, whether such vessels in humans possess this functionality is unknown. METHODS: Therefore, skeletal muscle feed arteries (~950 μm OD) from 10 humans (48 ± 4, 27-64 years) were studied using pressure myography. Vessel function was assessed using potassium chloride (KCl), phenylephrine (PE), acetylcholine (ACh) and sodium nitroprusside (SNP) concentration-response curves (CRCs) to characterize non-receptor and receptor-mediated vasoconstriction as well as endothelium-dependent and independent vasodilation respectively. To understand the physiological relevance of the diameter changes as a result of pharmacological stimulation, the estimated conductance ratio (CR) was calculated. RESULTS: Vessel function protocols revealed significant vasoconstriction in response to PE and KCl (35 ± 6; 43 ± 9%vasoconstriction, respectively) and significant vasodilation with ACh and SNP (85 ± 7; 121 ± 17% vasodilation, respectively). Both PE and KCl significantly reduced the CR (0.26 ± 0.05 and 0.23 ± 0.07, respectively), whereas ACh and SNP increased the CR (2.56 ± 0.10 and 5.32 ± 1.3, respectively). CONCLUSION: These novel findings provide evidence that human skeletal muscle feed arteries are capable of generating significant diameter changes that would translate into significant changes in vascular conductance. Thus, human skeletal muscle feed arteries likely play a significant role in regulating vascular conductance and subsequently blood flow in vivo

Outcomes of 1,327 Patients Operated on Through Twelve Multispecialty Surgical Volunteerism Missions: A Retrospective Cohort Study

BACKGROUND: Surgical volunteer missions (SVMs) have become a popular approach for reducing the burden of surgical disease worldwide. The aim of this study was to evaluate the outcomes of 12 surgical missions between 2006 and 2018 from the mission entitled Operation Giving Back Bohol Tagbilaran, Philippines and discuss the lessons learned during these missions in particular seven challenges that every volunteer surgeon should be familiar with. METHODS: This was a retrospective descriptive study of prospectively collected data on all patients treated during one SVM. The data collected included gender, age, diagnosis, types of surgeries performed, and perioperative adverse events. RESULTS: During the study period 1,327 operations were performed (842 females (63.4%) and 485 males (36.6%); (male-to-female ratio 0.59); mean age 37+/-18 years. The majority of operations were for thyroid disease (31.6%), followed by hernia (17.3%), hysterectomies/salpingo-oophorectomies (12.2%), soft tissue tumors (9.9%), cleft lip/palate repairs (7.2%), breast (6.4%), gallbladder disease (4.7%), cataract (2.9%), parotid masses (1.4%) and others (6.4%). For each mission, there were an average 5.5 days of operating, performing a median of 105.5 (80-148) cases per mission. There were 27 complications (2%), of which, 22 were postoperative bleeding and two temporary tracheostomies. The mortality rate was 0.15% (2/1327). In one patient, the family withdrew care following compassionate last ditch effort thyroidectomy for advanced cancer and one patient died as a result of intracranial bleeding from a brain tumor, which was unrecognized before mastectomy. CONCLUSIONS: Surgical volunteerism missions are safe and valuable in lessening the burden of surgical disease globally when performed in an organized fashion and with continuity of care. However, there is need for standardization of surgical care provided during SVMs and creation of a world-wide database of all SVMs, and each surgeon and others who participate in these mission should be familiar with critical elements and challenges for the successful mission

Prerandomization surgical training for the national surgical adjuvant breast and bowel project (NSABP) B-32 trial: A randomized phase III clinical trial to compare sentinel node resection to conventional axillary dissection in clinically node-negative breast cancer

OBJECTIVE: To train surgeons in a standardized technique of sentinel lymph node biopsy and to prepare them for the requirements of a prospective randomized surgical trial. SUMMARY BACKGROUND DATA: The NSABP B32 trial opened to accrual in May 1999. A significant component of this trial was a prerandomization training phase of surgeons performed by a group of core surgical trainers. The goals of this training phase were to expeditiously instruct surgeons in a standardized technique of sentinel lymph node biopsy and to educate those same surgeons in complete and accurate data collection and source documentation for the trial. METHODS: This study is a description of the training data collected in a prospective fashion for the training component for surgeon entry into the B32 trial, evaluating the effectiveness of the training program in regards to surgical outcomes and protocol compliance. RESULTS: Two hundred twenty-six registered surgeons underwent site visit training by a core surgical trainer and 187 completed training and were approved to randomize patients on the trial. The results of 815 training (nontrial) cases demonstrated a technical success rate for identifying sentinel nodes at 96.2% with a false negative rate of 6.7%. A protocol compliance analysis, which included the evaluation of 94 separate fields, showed mean protocol compliance of 98.6% for procedural fields, 95.5% for source documentation fields and 95.0% for data entry fields. CONCLUSIONS: This training and quality control program has resulted in a large number of surgeons capable of performing sentinel lymph node biopsy in a standardized fashion with a high degree of protocol compliance and pathologic accuracy. This will ensure optimal results for procedures performed on the randomized phase of the trial

Predictive factors of regional toxicity and serum creatine phosphokinase levels after isolated limb infusion for melanoma: a multi-institutional analysis.

BACKGROUND: Isolated limb infusion (ILI) is a minimally invasive technique delivering regional chemotherapy to treat in-transit extremity melanoma. Determining perioperative factors that could predict toxicity is important to optimize strategies to improve clinical outcomes after regional chemotherapy in melanoma. METHODS: Perioperative factors from 171 ILI patients performed at eight centers from 2001 to 2008 were reviewed. The Wieberdink limb toxicity scale and creatine phosphokinase (CK) levels were used to measure toxicity. Logistic regression analysis was used to estimate the association between toxicity and perioperative parameters. RESULTS: Mild (grades I-II) and severe (grades \u3eor=III) limb toxicity developed in 68% and 32% of patients, respectively. Melphalan adjusted for ideal body weight (aIBW) and papaverine were used in 47% and 63% of patients, respectively. Median peak CK for all patients was 563 U/l, and median peak occurred at postoperative day 4. On univariate analysis, papaverine and high CK levels (\u3e563 U/l) were significantly associated with higher toxicity. On the contrary, aIBW was significantly associated with a lower risk of severe toxicity. Perfusate blood gas at 30 min [pH, PaO(2), and base excess (BE) ], limb temperature, and ischemia time were not predictive of limb toxicity. On multivariate analysis, severe toxicity was associated with female sex (P = 0.01), papaverine (P = 0.01), and high peak CK levels (P \u3c 0.01). Independent predictors of high CK levels included younger age, unadjusted melphalan dose, and low PaO(2) at 30 min. CONCLUSIONS: ILI can be performed with an acceptable morbidity. Papaverine use, female gender, and high peak CK were associated with higher limb toxicity. CK levels can be diminished significantly with aIBW