bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comments on the dispersion relation method to vector–vector interaction
Authors: Molina R , Geng L S , Oset E 
Published: September 2019

Abstract
We study in detail the method proposed recently to study the vector–vector interaction using the $N/D$ method and dispersion relations, which concludes that, while, for $J=0$, one finds bound states, in the case of $J=2$, where the interaction is also attractive and much stronger, no bound state is found. In that work, approximations are done for $N$ and $D$ and a subtracted dispersion relation for $D$ is used, with subtractions made up to a polynomial of second degree in $s-s_\mathrm{th}$, matching the expression to $1-VG$ at threshold. We study this in detail for the $\rho\rho$ interaction and to see the convergence of the method we make an extra subtraction matching $1-VG$ at threshold up to $(s-s_\mathrm{th})^3$. We show that the method cannot be used to extrapolate the results down to 1270 MeV where the $f_2(1270)$ resonance appears, due to the artificial singularity stemming from the “on-shell” factorization of the $\rho$ exchange potential. In addition, we explore the same method but folding this interaction with the mass distribution of the $\rho$, and we show that the singularity disappears and the method allows one to extrapolate to low energies, where both the $(s-s_\mathrm{th})^2$ and $(s-s_\mathrm{th})^3$ expansions lead to a zero of $\mathrm{Re}\,D(s)$, at about the same energy where a realistic approach produces a bound state. Even then, the method generates a large $\mathrm{Im}\,D(s)$ that we discuss is unphysical.
YouTube resources for synthetic biology education
Authors: Dy Aaron J , Aurand Emily R , Friedman Douglas C 
Published: September 2019

Abstract
Online video resources have increasingly become a common way to effectively share scientific research ideas and engage viewers at many levels of interest or expertise. While synthetic biology is a comparatively young field, it has accumulated online videos across a spectrum of content and technical depth. Such video content can be used to introduce viewers to synthetic biology, supplement college course content, teach new lab skills and entertain. Here, we compile online videos concerning synthetic biology into public YouTube playlists tailored for six different, though potentially overlapping, audiences: those wanting an introduction to synthetic biology, those wanting to get quick overviews of specific topics within synthetic biology, those wanting teaching or public lectures, those wanting more technical research lectures, those wanting to learn lab protocols and those interested in the International Genetically Engineered Machine competition.
Variation in Entrustment When Sharing a Single Assessment System Between University- and Community-Based Residency Programs: A Comparison
Authors: Warm Eric J. , Kinnear Benjamin , Kelleher Matthew , Sall Dana , Schauer Daniel P. , Friedstrom Scott 
Published: September 2019

Purpose
Given resource constraints, many residency programs would consider adopting an entrustment-based assessment system from another program if given the opportunity. However, it is unclear if a system developed in one context would have similar or different results in another. This study sought to determine if entrustment varied between programs (community based and university based) when a single assessment system was deployed in different contexts.

Method
The Good Samaritan Hospital (GSH) internal medicine residency program adopted the observable practice activity (OPA) workplace-based assessment system from the University of Cincinnati (UC). Comparisons for OPA-mapped subcompetency entrustment progression for programs and residents were made at specific timepoints over the course of 36 months of residency. Data collection occurred from August 2012 to June 2017 for UC and from September 2013 to June 2017 for GSH.

Results
GSH entrustment ratings were higher than UC for all but the 11th, 15th, and 36th months of residency (P < .0001) and were also higher for the majority of subcompetencies and competencies (P < .0001). The rate of change for average monthly entrustment was similar, with GSH having an increase of 0.041 each month versus 0.042 for UC (P = .73). Most residents progressed from lower to higher entrustment, but there was significant variation between residents in each program.

Conclusions
Despite the deployment of a single entrustment-based assessment system, important outcomes may vary by context. Further research is needed to understand the contributions of tool, context, and other factors on the data these systems produce.
Nitrous Oxide Impairs Axon Regeneration after Nervous System Injury in Male Rats
Authors: Stewart Krista J. , Iskandar Bermans J. , Meier Brenton M. , Rizk Elias B. , Hariharan Nithya , Koueik Joyce , Andrei Adin-Christian , Hogan Kirk J. 
Published: September 2019

Abstract

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background
Nitrous oxide can induce neurotoxicity. The authors hypothesized that exposure to nitrous oxide impairs axonal regeneration and functional recovery after central nervous system injury.

Methods
The consequences of single and serial in vivo nitrous oxide exposures on axon regeneration in four experimental male rat models of nervous system injury were measured: in vitro axon regeneration in cell culture after in vivo nitrous oxide administration, in vivo axon regeneration after sharp spinal cord injury, in vivo axon regeneration after sharp optic nerve injury, and in vivo functional recovery after blunt contusion spinal cord injury.

Results

In vitro axon regeneration 48 h after a single in vivo 70% N2O exposure is less than half that in the absence of nitrous oxide (mean ± SD, 478 ± 275 um; n = 48) versus 210 ± 152 um (n = 48; P < 0.0001). A single exposure to 80% N2O inhibits the beneficial effects of folic acid on in vivo axonal regeneration after sharp spinal cord injury (13.4 ± 7.1% regenerating neurons [n = 12] vs. 0.6 ± 0.7% regenerating neurons [n = 4], P = 0.004). Serial 80% N2O administration reverses the benefit of folic acid on in vivo retinal ganglion cell axon regeneration after sharp optic nerve injury (1277 ± 180 regenerating retinal ganglion cells [n = 7] vs. 895 ± 164 regenerating retinal ganglion cells [n = 7], P = 0.005). Serial 80% N2O exposures reverses the benefit of folic acid on in vivo functional recovery after blunt spinal cord contusion (estimate for fixed effects ± standard error of the estimate: folic acid 5.60 ± 0.54 [n = 9] vs. folic acid + 80% N2O 5.19 ± 0.62 [n = 7], P < 0.0001).

Conclusions
These data indicate that nitrous oxide can impair the ability of central nervous system neurons to regenerate axons after sharp and blunt trauma.
Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery
Authors: Kang RyungA , Jeong Ji Seon , Chin Ki Jinn , Yoo Jae Chul , Lee Jong Hwan , Choi Soo Joo , Gwak Mi Sook , Hahm Tae Soo , Ko Justin Sangwook 
Published: September 2019

Abstract

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background
Interscalene brachial plexus block of the C5–C6 roots provides highly effective postoperative analgesia after shoulder surgery but usually results in hemidiaphragmatic paresis. Injection around the superior trunk of the brachial plexus is an alternative technique that may reduce this risk. The authors hypothesized that the superior trunk block would provide noninferior postoperative analgesia compared with the interscalene block and reduce hemidiaphragmatic paresis.

Methods
Eighty patients undergoing arthroscopic shoulder surgery were randomized to receive a preoperative injection of 15 ml of 0.5% ropivacaine and 5 μg · ml−1 epinephrine around either (1) the C5–C6 nerve roots (interscalene block group) or (2) the superior trunk (superior trunk block group). The primary outcome was pain intensity 24 h after surgery measured on an 11-point numerical rating score; the prespecified noninferiority limit was 1. Diaphragmatic function was assessed using both ultrasonographic measurement of excursion and incentive spirometry by a blinded investigator before and 30 min after block completion.

Results
Seventy-eight patients completed the study. The pain score 24 h postoperatively (means ± SDs) was 1.4 ± 1.0 versus 1.2 ± 1.0 in the superior trunk block (n = 38) and interscalene block (n = 40) groups, respectively. The mean difference in pain scores was 0.1 (95% CI, −0.3 to 0.6), and the upper limit of the 95% CI was lower than the prespecified noninferiority limit. Analgesic requirements and all other pain measurements were similar between groups. Hemidiaphragmatic paresis was observed in 97.5% of the interscalene block group versus 76.3% of the superior trunk block group (P = 0.006); paresis was complete in 72.5% versus 5.3% of the patients, respectively. The decrease in spirometry values from baseline was significantly greater in the interscalene block group.

Conclusions
The superior trunk block provided noninferior analgesia compared with interscalene brachial plexus block for up to 24 h after arthroscopic shoulder surgery and resulted in significantly less hemidiaphragmatic paresis.
Limited Endoscopic-Assisted Wedge Resection for Excision of Colon Polyps
Authors: Leicher Laura W. , de Vos tot Nederveen Cappel Wouter H. , van Westreenen Henderik L. 
Published: September 2019

BACKGROUND:
Combined endoscopic laparoscopic surgical removal is used for polyps in the colon that are not suitable for endoscopic removal because of size, location, or scarring. However, the placement of a linear stapler can be challenging. Currently a wedge resection is mostly documented in the cecum or ascending colon.

OBJECTIVE:
We report on our experience with limited endoscopy-assisted wedge resections in the entire colon.

DESIGN:
A retrospective study was performed.

SETTINGS:
This was a single-center study.

PATIENTS:
Eight patients were included between March 2015 and April 2016.

INTERVENTIONS:
The laparoscopic surgical technique consisted of placing a suture under endoscopic view through the base of the polyp into the lumen. Subsequently, traction was given on the suture to enable stapling of a wedge of the colon.

MAIN OUTCOME MEASURES:
Medical data were collected (ie, indication for referral for surgery, location and size of the polyp, duration of surgical procedure, length of hospital stay, and perioperative and postoperative complications). Operative time was defined as the total time of general anesthesia.

RESULTS:
Eight patients, with a mean age of 74.5 years (range, 68.0–82.0 years), were treated. The main indications for laparoscopic resection were the size and difficult location of the polyp. There were no complications. Mean operative time was 132 minutes. Five patients were discharged the day after surgery, and the other 3 patients were admitted for a total of 2 days.

LIMITATIONS:
The study was limited by its small sample size.

CONCLUSIONS:
Our study found that limited endoscopy-assisted wedge resection is a feasible and easy technique for the removal of colon polyps and residual adenomatous tissue in scars that are not accessible for endoscopic removal. Because of traction given on the suture through the base of the polyp, the linear stapler is easily used for wedge resections of polyps, even for those that are not in favorable positions.
Short- and Long-term Outcomes of Laparoscopic Total Mesenteric Excision for Neuroendocrine Tumors of the Rectum
Authors: Takatsu Yukiko , Fukunaga Yosuke , Nagasaki Toshiya , Akiyoshi Takashi , Konishi Tsuyoshi , Fujimoto Yoshiya , Nagayama Satoshi , Ueno Masashi 
Published: September 2019

BACKGROUND:
To our knowledge, no studies to date have assessed the short- and long-term outcomes of laparoscopic total mesenteric excision in patients with neuroendocrine tumors of the rectum.

OBJECTIVE:
The purpose of this study was to investigate the short- and long-term outcomes of patients who underwent laparoscopic rectal resection plus total mesenteric excision for rectal neuroendocrine tumors at our institution.

DESIGN:
This was a single center, retrospective study.

SETTINGS:
The study was conducted at a tertiary care facility.

PATIENTS:
Eight-two patients with neuroendocrine tumors who underwent rectal resection with total mesenteric excision, 77 laparoscopically, between June 2005 and August 2015 were included.

INTERVENTIONS:
Laparoscopic rectal resection and total mesenteric excision were the study interventions.

MAIN OUTCOME MEASURES:
Demographic characteristics and surgical and postoperative outcomes were measured.

RESULTS:
Median tumor size was 8.8 mm (range, 3.0–35.0 mm); 63.6% of tumors were located in the lower rectum, with the median distance from the tumor to the anal verge being 50.0 mm (range, 20.0–130.0 mm). Anal preservation was achieved in all of the patients. Anastomotic leakage occurred in 5 patients (6.5%), but there were no deaths. Seventy-one patients (92.2%) had tumor invasion confined to the submucosa. Lymph node metastasis was present in 29 patients (37.7%), including 26 (33.8%) with perirectal and 5 (6.5%) with lateral lymph node metastasis. The median follow-up period in 59 patients was 42 months (range, 11–113 months), and the 3-year overall survival rate was 97.8%.

LIMITATIONS:
The study was limited by its single-center, retrospective analysis.

CONCLUSIONS:
Laparoscopic rectal resection with total mesenteric excision is safe in patients with rectal neuroendocrine tumors, with good short- and long-term outcomes. Because rectal neuroendocrine tumors are smaller and show superficial invasion, the rate of anal preservation may be high.
Outcome and Salvage Surgery Following “Watch and Wait” for Rectal Cancer after Neoadjuvant Therapy: A Systematic Review
Authors: Kong Joseph C. , Guerra Glen R. , Warrier Satish K. , Ramsay Robert G. , Heriot Alexander G. 
Published: September 2019

BACKGROUND:
Currently there is no reliable test to predict pathological complete response following neoadjuvant chemoradiotherapy for rectal cancer. However, there is increasing interest in using clinical complete response as a surrogate marker, allowing a subset of patients with locally advanced rectal cancer to be allocated into a “watch and wait” pathway. Little is known about the oncological safety of the “watch and wait” approach or the rate of salvage surgery in cases of tumor regrowth. This information is critical for the implementation of this approach.

OBJECTIVE:
The aim of this study is to assess the rate of salvage surgery and associated oncological outcomes for patients who develop a tumor regrowth with the “watch and wait” approach.

DATA SOURCES:
Relevant studies were identified through PubMed, Embase, and Google Scholar search.

STUDY SELECTION:
A systematic review was undertaken of studies assessing patients selected for the “watch and wait” approach according to PRISMA guidelines.

MAIN OUTCOME MEASURES:
The associated tumor regrowth, salvage surgery, and disease-free and overall survival rates were assessed.

RESULTS:
Five retrospective and 4 prospective observational studies were included into the analysis, with a total of 370 patients in the “watch and wait” group, of which 256 (69.2%) had persistent clinical complete response. Of those who had tumor regrowth, salvage surgery was possible in 83.8%. There was no difference in overall survival and disease-free survival between patients who received immediate surgery and the “watch and wait” group.

LIMITATIONS:
The limitations of this study include its retrospective nature and small sample size. Furthermore, there is significant heterogeneity between study protocols, including the short median follow-up, given that tumor regrowth and distant metastasis may manifest at a later time point.

CONCLUSION:
The majority of patients with tumor regrowth can be salvaged with definite surgery after “watch and wait.” However, there is insufficient evidence to draw firm conclusions on the oncological safety of this approach; therefore, it is currently not the standard of care for locally advanced rectal cancer.
Efficacy and Safety of High-Intensity Focused Ultrasound for Noninvasive Abdominal Subcutaneous Fat Reduction
Authors: Hong Ji Yeon , Ko Eun Jung , Choi Sun Young , Kwon Tae-Rin , Kim Jong Hwan , Kim Soo Yeon , Kim Beom Joon 
Published: September 2019

BACKGROUND
Demand for noninvasive body contouring has increased.

OBJECTIVE
We evaluated the efficacy and safety of a thermal high-intensity focused ultrasound (HIFU) device for abdominal body shaping.

PATIENTS AND METHODS
Adults with a body mass index ≤30 kg/m2 and an abdominal subcutaneous fat tissue thickness ≥2.5 cm were enrolled for HIFU treatment at energy levels of 150 J/cm2 (first session) and 135 J/cm2 (second session). The primary end point was a change from baseline waist circumference at post‐treatment Week 8. Secondary efficacy end points were: changes in body weight, waist/hip ratio, and fat thickness assessed by ultrasound, caliper, and a fat CT scan. The Global Aesthetic Improvement Scale was evaluated by both investigators and subjects.

RESULTS
The primary assessment achieved statistical significance, showing a reduction of 3.43 cm in mean waist circumference. The treatment effect was cumulative, with a steady decrease in waist circumference and fat thickness. The mean pain scores immediately after treatment were 4.45 ± 2.74 on a scale of 1 to 10 with 10 being the most painful, which decreased to 1.10 ± 1.33 after 1 week.

CONCLUSION
High-intensity focused ultrasound is an effective and safe treatment modality for reducing waist circumference in nonobese individuals with focal fat accumulation.
Safety of Periocular Mohs Reconstruction: A Two-Center Retrospective Study
Authors: Clark Matthew L. , Kneiber Diana , Neal Donald , Etzkorn Jeremy , Maher Ian A. 
Published: September 2019

BACKGROUND
Repair of periocular defects poses unique functional and aesthetic challenges. Data on the safety of periocular repairs by Mohs surgeons are limited.

OBJECTIVE
Analyze the frequency and types of postreconstruction complications encountered with periocular repairs performed by Mohs surgeons, identify risk factors associated with complications, and enumerate interventions for complications encountered.

MATERIALS AND METHODS
An institutional review board–approved retrospective study on periocular repairs performed by Mohs surgeons at 2 academic institutions between 07 2013 and 06 2016. Patients undergoing periocular Mohs surgery were identified via billing codes. Patient demographics and surgery details were recorded. Follow-up visit notes were reviewed for postoperative complications and interventions performed.

RESULTS
Two hundred ten cases were included in the analysis. The most common locations for postreconstruction complications were the medial canthus (57%) and lower eyelid (37%). The complications identified included medial canthal webbing (4.3%), hypertrophic scarring (4.3%), ectropion (1.9%), infection (1.4%), pincushioning (1.4%), and epiphora (1.0%). The most common postoperative intervention was intralesional triamcinolone. Scar revision was performed in 2.4% of all cases.

CONCLUSION
Periocular repairs performed by Mohs surgeons have a similar safety profile as repairs performed by oculoplastic surgeons.
Sequential Scalp Assessment in Hair Regeneration Therapy Using an Adipose-Derived Stem Cell–Conditioned Medium
Authors: Narita Keigo , Fukuoka Hirotaro , Sekiyama Takuya , Suga Hirotaka , Harii Kiyonori 
Published: September 2019

BACKGROUNDAn adipose-derived stem cell–conditioned medium (ADSC-CM) reportedly exerts skin-rejuvenating and hair growth-promoting effects. In the therapeutic application of ADSC-CM for alopecia, changes to the interfollicular scalp remain unclear although some evidence has indicated hair growth-promoting effects.OBJECTIVETo evaluate the effects of ADSC-CM not only on hair follicles, but also on the interfollicular scalp.METHODSForty patients (21 men, 19 women; age range, 23–74 years) with alopecia were treated by intradermal injection of ADSC-CM every month for 6 months. Eighty fixed sites on patients were investigated by trichograms, physiological examinations, and ultrasonographic examinations at 4 time points (before treatment and 2, 4, and 6 months after the initial treatment).RESULTSHair density and anagen hair rate increased significantly. As physiological parameters, transepidermal water loss value gradually increased, with significant differences at 4 and 6 months after the initial treatment, but hydration state of the stratum corneum and skin surface lipid level showed no obvious changes. As ultrasonographic parameters, dermal thickness and dermal echogenicity were increased significantly.CONCLUSIONIntradermal administration of ADSC-CM on the scalp has strong potential to provide regenerative effects for hair follicles and the interfollicular scalp. An adipose-derived stem cell–conditioned medium offers a promising prospect as an alternative treatment for alopecia.
An 18-year Study of Malignant Melanoma in Childhood and Adolescence
Authors: Al-Himdani Sarah , Naderi N. , Whitaker I.S. , Jones N.W. 
Published: September 2019

Background:
Malignant melanoma is rare in childhood and adolescence. Diagnostic uncertainty and misdiagnosis often lead to delayed treatment.

Methods:
We evaluated children and adolescents under 20 years of age presenting with malignant melanoma at our institution over an 18-year period. Data were collected, analyzed, and interpreted, following which findings were compared with the existing literature.

Results:
Twenty-four patients were included in the study with mean follow-up of 61.8 months. Males comprised 54% of cases. On presentation, 33% of children had melanoma of s thickness 2–4 mm and 34% had stage III disease. Younger children presented with thicker melanomas, differing subtypes, and more advanced stage disease compared with older children. Extremities were the most common sites affected (42%). Dissection of the draining lymph node basins was undertaken in 38% of cases. Overall survival was 92%.

Conclusions:
Tumor subtype, biology, hormonal influence, and lymph node status are all important prognostic factors in malignant melanoma in childhood and adolescence. Compared with adults, children presenting with thicker melanomas and more advanced stage disease generally have more favorable outcomes and a better survival. Plastic surgeons, commonly encountering skin lesion in children, must maintain a high index of suspicion so that early excision and sentinel lymph node biopsy may be promptly offered to patients with melanoma.
EFFECT OF LUBRICANTS ON CORNEAL THICKNESS AFTER VITRECTOMY
Authors: Siegel Diane T. , Hubbard G. Baker , Yan Jiong , Cribbs Blaine , Jain Nieraj , Yeh Steve , Bui Diem , Smith Jesse , Barb Scott , Pearce William , Ward Laura , Hendrick Andrew M. 
Published: September 2019

Purpose:
This study examines the impact of corneal surface lubricants used during pars plana vitrectomy on corneal edema.

Methods:
This prospective, observational, clinical study occurred at an academic institution. Participants were individuals aged 18 years and older who had already consented to undergo pars plana vitrectomy, without pre-existing corneal pathology. A corneal lubricant was chosen by the surgeon. Corneal thickness was measured preoperatively and postoperatively using pachymetry and anterior segment optical coherence tomography (AS-OCT). Main outcome measure was change in corneal thickness as measured by pachymetry.

Results:
Forty-one patients completed the study protocol. The 23 subjects in the SHCS group had a significantly smaller increase in corneal thickness as measured by pachymetry compared with the 18 subjects in the HPMC group (29.9 μm vs. 58.1 μm, P value 0.02). When measured by anterior segment optical coherence tomography, the SHCS group had a smaller increase in corneal thickness compared with the HPMC group (0.04 mm vs. 0.06 mm, P value 0.09) but did not reach significance.

Conclusion:
SHCS is associated with reduced postoperative increase in corneal pachymetry as compared to HPMC.