bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitric oxide releasing vascular catheters for eradicating bacterial infection
Authors: Pant Jitendra , Goudie Marcus J. , Chaji Sarah M. , Johnson Benjamin W. , Handa Hitesh
Published: December 2017

The interaction of blood proteins with an implant surface is not only a fundamental phenomenon but is also key to several important medical complications. Plasma proteins binding on the surface of intravascular catheters can promote bacterial adhesion leading to the risk of local and systemic complications such as catheter‐related blood infections (CRBIs). The incidences of CRBIs in the United States amount to more than 250,000 cases/year with an attributable mortality of up to 35% and an annual healthcare expenditure of $2.3 billion approximately. This demands the development of truly nonthrombogenic and antimicrobial catheters. In the present study, catheters were fabricated by incorporating a nitric oxide (NO) donor molecule, S‐nitroso‐N‐acetyl‐penicillamine (SNAP) in a hydrophobic medical grade polymer, Elasteon‐E2As. NO offers antithrombotic and antibacterial attributes without promoting drug resistance and cytotoxicity. E2As‐SNAP catheters were first coated with fibrinogen, a blood plasma protein plays a key role in clot formation and eventual bacterial adhesion to the implant surface. The suitability of the catheters for biomedical applications was tested in vitro for contact angle, NO release kinetics, inhibition of bacteria, and absence of cytotoxicity toward mammalian cells. The highly hydrophobic catheters released NO in the physiological range that inhibited >99% bacterial viability on fibrinogen‐coated catheters in a 24 h study. No toxic response of E2As‐SNAP catheters leachate was observed using a standard cytotoxicity assay with mouse fibroblast cells. Overall, the results showed that the E2As‐SNAP catheters can inhibit viable bacteria even in the presence of blood proteins without causing a cytotoxic response. The fundamentals of this study are applicable to other blood‐contacting medical devices as well. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2849–2857, 2018.
Development of non‐bonded interaction parameters between graphene and water using particle swarm optimization
Authors: Bejagam Karteek K. , Singh Samrendra , Deshmukh Sanket A.
Published: December 2017

New Lennard‐Jones parameters have been developed to describe the interactions between atomistic model of graphene, represented by REBO potential, and five commonly used all‐atom water models, namely SPC, SPC/E, SPC/Fw, SPC/Fd, and TIP3P/Fs by employing particle swarm optimization (PSO) method. These new parameters were optimized to reproduce the macroscopic contact angle of water on a graphene sheet. The calculated line tension was in the order of 10−11 J/m for the droplets of all water models. Our molecular dynamics simulations indicate the preferential orientation of water molecules near graphene–water interface with one OH bond pointing toward the graphene surface. Detailed analysis of simulation trajectories reveals the presence of water molecules with ≤∼1, ∼2, and ∼4 hydrogen bonds at the surface of air–water interface, graphene–water interface, and bulk region of the water droplet, respectively. Presence of water molecules with ≤∼1 and ∼2 hydrogen bonds suggest the existence of water clusters of different sizes at these interfaces. The trends observed in the libration, bending, and stretching bands of the vibrational spectra are closely associated with these structural features of water. The inhomogeneity in hydrogen bond network of water at the air–water and graphene–water interface is manifested by broadening of the peaks in the libration band for water present at these interfaces. The stretching band for the molecules in water droplet shows a blue shift as compared to the pure bulk water, which conjecture the presence of weaker hydrogen bond network in a droplet. © 2017 Wiley Periodicals, Inc.
Peptide selectivity between the PDZ domains of human pregnancy‐related serine proteases (HtrA1, HtrA2, HtrA3, and HtrA4) can be reshaped by different halogen probes
Authors: Sun Mei‐Ling , Sun Li‐Mei , Wang Yong‐Qing
Published: December 2017

The human HtrA family of serine proteases (HtrA1, HtrA2, HtrA3, and HtrA4) are the key enzymes associated with pregnancy and closely related to the development and progression of many pathological events. Previously, it was found that halogen substitution at the indole moiety of peptide Trp‐1 residue can form a geometrically satisfactory halogen bond with the Drosophila discs large, zona occludens‐1 (PDZ) domain of HtrA proteases. Here, we attempt to systematically investigate the effect of substitution with 4 halogen types and 2 indole positions on the binding affinity and specificity of peptide ligands to the 4 HtrA PDZ domains. The complex structures, interaction energies, halogen‐bonding strength, and binding affinity of domain‐peptide systems were modeled, analyzed, and measured via computational modeling and fluorescence‐based assay. It is revealed that there is a compromise between the local rearrangement of halogen bond involving different halogen atoms and the global optimization of domain‐peptide interaction; the substitution position is fundamentally important for peptide‐binding affinity, while the halogen type can effectively shift peptide selectivity between the 4 domains. The HtrA1‐PDZ and HtrA4‐PDZ as well as HtrA2‐PDZ and HtrA3‐PDZ respond similarly to different halogen substitutions of peptide; –Br substitution at R2‐position and –I substitution at R4‐position are most effective in improving peptide selectivity for HtrA1‐PDZ/HtrA4‐PDZ and HtrA2‐PDZ/HtrA3‐PDZ, respectively; –F substitution would not address substantial effect on peptide selectivity for all the 4 domains. Consequently, the binding affinities of a native peptide ligand DSRIWWV–COOH as well as its 4 R2‐halogenated counterparts were determined as 1.9, 1.4, 0.5, 0.27, and 0.92 μM, which are basically consistent with computational analysis. This study would help to rationally design selective peptide inhibitors of HtrA family members by using different halogen substitutions.
Societal individualism–collectivism and uncertainty avoidance as cultural moderators of relationships between job resources and strain
Authors: Jang Seulki , Shen Winny , Allen Tammy D. , Zhang Haiyan
Published: December 2017

The job demands–resources model is a dominant theoretical framework that describes the influence of job demands and job resources on employee strain. Recent research has highlighted that the effects of job demands on strain vary across cultures, but similar work has not explored whether this is true for job resources. Given that societal characteristics can influence individuals' cognitive structures and, to a lesser extent, values in a culture, we address this gap in the literature and argue that individuals' strain in reaction to job resources may differ across cultures. Specifically, we theorize that the societal cultural dimensions of individualism–collectivism and uncertainty avoidance shape individual‐level job resource–strain relationships, as they dictate which types of resources (i.e., individual vs. group preference‐oriented and uncertainty‐reducing vs. not) are more likely to be valued, used, or effective in combating strain within a culture. Results revealed that societal individualism–collectivism and uncertainty avoidance independently moderated the relationships between certain job resources (i.e., job control, participation in decision making, and clear goals and performance feedback) and strain (i.e., job satisfaction and turnover intentions). This study expands our understanding of the cross‐cultural specificity versus generalizability of the job demands–resources model.
Effect of modulating dietary vitamin D on the general bone health of rats during posterolateral spinal fusion
Authors: Bhamb Neil , Kanim Linda , Maldonado Ruben , Svet Mark , Metzger Melodie
Published: December 2017

Vitamin D plays a significant role in musculoskeletal health by regulating calcium, phosphate, and promoting new bone mineralization. The purpose of this study was to understand the effect of dietary vitamin D on general bone health during peri‐operative bone healing via an in vivo dosing study of vitamin D in a rat posterolateral fusion model using autograft. Vitamin D Deficient (DD), vitamin D Insufficient (ID), Control vitamin D (CD), and Hyper‐vitamin D (HD) groups were studied. Increasing dietary vitamin D improved quantitative measures of femoral geometry, including femoral strength, stiffness, and density. Femoral biomechanics, cortical thickness, moment of inertia, cross‐sectional area, and measures from bone ashing were all greater in the HD group versus the CD. This suggests that additional dietary vitamin D above normal levels during spinal fusion may lead to improvement in bone health. Serum vitamin D levels were also observed to decrease during fusion healing. These results demonstrate that dietary vitamin D improves general bone health in the femur of a rat model during posterolateral spinal fusion. This suggests a role for further clinical evaluation of vitamin D dietary intake during the peri‐operative period, with the possibility of avoiding adverse consequences to general bone health. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1435–1443, 2018.
A novel purple acid phytase from an earthworm cast bacterium
Authors: Ghorbani Nasrabadi Reza , Greiner Ralf , Yamchi Ahad , Nourzadeh Roshan Elham
Published: December 2017

BACKGROUND

Phytases are a diverse group of enzymes initiating the dephosphorylation of phytate. Phytate is considered as an anti‐nutritional compound because of its capability to chelate nutrients such as Fe2+, Zn2+, Mg2+, and Ca2+. In this study, several bacterial isolates obtained from earthworm casts were evaluated for their phytate degrading capability. Enzymatic properties and the sequence of the corresponding phytase‐encoding gene of the selected isolate were determined.

RESULTS

The phytase exhibited its highest activity at pH 4.0 and was stable from pH 3 up to pH 9. The temperature optimum was determined to be 65 °C. The strongest inhibitors of enzymatic activity were identified as vanadate, Cu2+, and Zn2+. High‐performance ion chromatography analysis of enzymatic phytate dephosphorylation revealed that the first dephosphorylation product was d/l‐myo‐inositol(1,2,3,4,5)pentakisphosphate.

CONCLUSION

Owing to its enzymatic properties, such as tolerance to tartrate and the presence of the consensus motifs PDTVY, GNHE, DLG, VLFH, and GHDH, this phytase could be classified as a purple acid phytase. To the best of our knowledge, this is the first report describing a bacterial purple acid phytase. © 2017 Society of Chemical Industry
Prognostic models for RPS patients—Attempting to predict patient outcomes
Authors: Callegaro Dario , Miceli Rosalba , Gladdy Rebecca A.
Published: December 2017

Retroperitoneal sarcoma (RPS) patients can have variable of outcomes after surgery. The chance to recur locally or at distant sites varies according to tumor grade, histologic subtype, and other patient‐ and tumor‐related characteristics. The relative contribution of each prognostic variable on the oncological outcome of RPS patients can be weighted by combining them in prognostic tools such as nomograms. With this review, we critically appraise the available nomograms for RPS patients highlighting pros and cons.
Clinicopathological characteristics, staging classification, and survival outcomes of primary malignant melanoma of the esophagus
Authors: Sun Haiyan , Gong Lei , Zhao Gang , Zhan Hongdian , Meng Bin , Yu Zhentao , Pan Zhanyu
Published: December 2017

Background

Primary malignant melanoma of esophagus (PMME) is a remarkably rare and highly aggressive tumor. Studies related with clinicopathological findings, staging classification, and clinical outcomes are lacking.

Methods

We reviewed 21 cases of PMME at the Tianjin Medical University Cancer Institute and Hospital from January 2002 to February 2017.

Results

Nineteen patients (90.48%) presented a history of dysphagia for months, and two (9.52%) experienced retrosternal pain. Histologically, tumors were composed of atypical melanocytes with melanocytosis surrounding the tumor. The overall survival was 1‐40 months, with the median time of 10 months. The mucosal staging classification for upper aerodigestive tract showed better distribution of overall survival with different stages than that of the American Joint Commission on Cancer staging classification for esophagus, but without statistical difference. Both the clinical and pathological characteristics were not highly consistent with overall survival.

Conclusions

PMME is a considerably aggressive tumor with poor prognosis. The staging classification of mucosal melanoma of the upper aerodigestive tract may be a good option for PMME patients.
5‐fluorouracil combined with cisplatin and mitomycin C as an optimized regimen for hyperthermic intraperitoneal chemotherapy in gastric cancer
Authors: Murata Satoshi , Yamamoto Hiroshi , Shimizu Tomoharu , Naitoh Hiroyuki , Yamaguchi Tsuyoshi , Kaida Sachiko , Takebayashi Katsushi , Miyake Toru , Tani Tohru , Tani Masaji
Published: December 2017

Background and Objectives

Optimized drug regimens for hyperthermic intraperitoneal chemotherapy (HIPEC) have not been standardized completely in patients with advanced gastric cancer (GC). We evaluated an optimized anti‐tumor protocol comprising 5‐fluorouracil (5‐FU) combined with cisplatin (CDDP) and mitomycin C (MMC) in vitro for clinical use of HIPEC.

Methods

The sensitivities of 5‐FU, CDDP, or MMC, alone or in combination, using different drug concentrations, exposure times, and hyperthermic conditions (42°C) were determined in vitro by the CD‐DST method using 3 different differentiated GC cell lines.

Results

The tumor cell growth‐inhibitory effect of 5‐FU was concentration‐dependent for all cell lines. In addition, 5‐FU showed a hyperthermic sensitization effect at all drug concentrations for all cell lines. The appropriate concentration of each drug was 5‐FU, 200 µg/mL; CDDP, 10 µg/mL; MMC, 2 µg/mL. Under hyperthermic conditions, most growth‐inhibitory effects for each drug at 30 min was equivalent to 60 min of exposure; use of three drugs combined significantly inhibited growth compared with any of the drugs alone.

Conclusion

An appropriate in vitro intraperitoneal chemotherapy regimen for GC was combined use of 5‐FU, CDDP, and MMC at 42°C for 30 min.
CEA to peritoneal carcinomatosis index (PCI) ratio is prognostic in patients with colorectal cancer peritoneal carcinomatosis undergoing cytoreduction surgery and intraperitoneal chemotherapy
Authors: Kozman Mathew A. , Fisher Oliver M. , Rebolledo Bree‐Anne J. , Parikh Roneil , Valle Sarah J. , Arrowaili Arief , Alzahrani Nayef , Liauw Winston , Morris David L.
Published: December 2017

Background and Objectives

Serum tumor markers are prognostic in patients with colorectal cancer peritoneal carcinomatosis (CRPC) undergoing cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC). Assessment of the ratio of tumor marker to volume, as depicted by peritoneal carcinomatosis index (PCI), and how this may affect overall (OS) and recurrence free survival (RFS) has not been reported.

Methods

Survival effect of this ratio was analyzed in patients with CRPC managed from 1996 to 2016 with CRS and IPC.

Results

Of 260 patients included, those with low CEA/PCI ratio (<2.3) had longer median OS (56 vs 24 months, P = 0.001) and RFS (13 vs 9 months, P = 0.02). The prognostic impact of CEA/PCI ratio was most pronounced in patients with PCI ≤ 10 (OS of 72 vs 30 months, P < 0.001; RFS of 21 vs 10 months, P = 0.002). In multivariable analysis, elevated CEA/PCI ratio was independently associated with poorer OS (adjusted HR 1.85, 95%CI 1.11‐3.10, P = 0.02) and RFS (adjusted HR 1.58, 95%CI 1.04‐2.41, P = 0.03).

Conclusion

CEA/PCI ratio is an independent prognostic factor for OS and RFS in CRPC. This novel approach allows both tumor activity and volume to be accounted for in one index, thus potentially providing a more accurate indication of tumor biological behavior.
Soft tissue tumors of the pelvis: Technical and histological considerations
Authors: Mullen John T. , van Houdt Winan
Published: December 2017

In this review, we first address the anatomic and technical considerations in the resection of pelvic soft tissue tumors, including the challenges unique to these tumors, such as the narrow anatomic confines of the bony pelvis, the often locally aggressive nature of these tumors, as well as the major functional deficits that may result from their resection. We then review the optimal, multidisciplinary, histology‐driven treatment approach to pelvic tumors.
Survival in patients with medullary thyroid cancer after less than the recommended initial operation
Authors: Randle Reese W. , Bates Maria F. , Schneider David F. , Sippel Rebecca S. , Pitt Susan C.
Published: December 2017

Background and Objectives

We aimed to evaluate the disease specific‐survival (DSS) of patients with Medullary Thyroid Cancer (MTC) confined to the central neck based on the extent of the initial operation.

Methods

This retrospective review of patients with MTC from the SEER registry from 2004 to 2012 excluded patients with lateral neck involvement or distant metastases.

Results

The cohort (n = 766) included 85(11%) less than total thyroidectomies (TT), 212(28%) TT alone, and 469(61%) TT with lymph node excision. Mean tumor size was similar (2.2cm for <TT, 1.9 for TT alone, and 2.2 for TT with nodes, p=0.13). Patients receiving a TT with nodal excision were more likely to have multifocal tumors (8% <TT, 22% TT alone, and 27% TT with nodes, P < 0.001), and extrathyroidal extension (1% <TT, 4% TT alone, and 9% TT with nodes, P = 0.005). Even after controlling for significant predictors of DSS, extent of the initial operation did not predict survival (HR 0.28 for <TT, 95% CI 0.26‐3.11 and HR 0.62 for TT alone, 95% CI 0.17‐2.22 compared to TT with nodes, P = NS for all).

Conclusion

According to population‐based SEER registry data, the extent of initial resection may not significantly change DSS in patients with MTC confined to the central neck.
Conflict at work, job embeddedness, and their effects on intention to quit among women employed in travel agencies: Evidence from a religious city in a developing country
Authors: Khorakian Alireza , Nosrati Saeid , Eslami Ghasem
Published: December 2017

Intention to quit is an important concern in organizations active in the tourism industry. This issue is more evident among the employed women in religious developing countries due to the cultural and environmental conditions. This study aimed to examine the mediating role of job embeddedness and the antecedents including work–leisure conflict, work–family conflict, and work overload on intention to quit. Data were collected from 618 female employees working in travel agencies. The results showed that the negative effects on the work‐leisure conflict, work‐family conflict and work overload led to a reduction in job embeddedness and an increase in their intention to quit.
Lung Ultrasound Findings Detected During Inpatient Echocardiography Are Common and Associated With Short‐ and Long‐term Mortality
Authors: Garibyan Vartan N. , Amundson Stanley A. , Shaw David J. , Phan James N. , Showalter Brian K. , Kimura Bruce J.
Published: December 2017

Objectives

Although pulmonary abnormalities are easily seen with standard echocardiography or pocket‐sized ultrasound devices, we sought to observe the prevalence of lung ultrasound apical B‐lines and pleural effusions and their associations with inpatient, 1‐year, and 5‐year mortality when found in hospitalized patients referred for echocardiography.

Methods

We reviewed 486 initial echocardiograms obtained from consecutive inpatients over a 3‐month period, in which each examination included 4 supplemental images of the apex and the base of both lungs. Kaplan‐Meier survival curves were used to compare mortality rates among patients with versus without lung findings. Cox proportional hazard regression was used to determine the relative contributions of age, sex, effusions, and B‐lines to overall mortality.

Results

Of the 486 studies, the mean patient age ± SD was 68 ± 17 years; the median age was 70 years (interquartile range, 27 years); and 191 (39%) had abnormal lung findings. The presence versus absence of abnormal lung findings was related to initial‐hospital (8.9% versus 2.0%; P = .001), 1‐year (33% versus 14%; P < .001), and 5‐year (56% versus 31%; P < .001) mortality. Ultrasound apical B‐lines and pleural effusions were both independently associated with increased mortality during initial hospitalization (hazard ratio [HR], 4.3; 95% confidence interval [CI], 1.7–11.0; and HR, 2.5; 95% CI, 1.1–6.0, respectively). Pleural effusions were also associated with increased 1‐year mortality (HR, 2.3; 95% CI, 1.5–3.4).

Conclusions

In hospitalized patients undergoing echocardiography, the simple addition of 4 quick 2‐dimensional pulmonary views to the echocardiogram often detects abnormal findings that have important implications for short‐ and long‐term mortality.
Effect of laser therapy on quality of life in patients with radiation‐induced breast telangiectasias
Authors: Rossi Anthony M. , Blank Nina R. , Nehal Kishwer , Dusza Stephen , Lee Erica H.
Published: December 2017

Objective

To evaluate the effects of laser monotherapy on quality of life in breast cancer patients with chronic radiation dermatitis.

Study Design

A prospective, IRB‐approved study was conducted at Memorial Sloan Kettering Cancer Center. Breast cancer patients with chronic radiation dermatitis completed health‐related quality of life (HR‐QOL) questionnaires before and after laser monotherapy for radiation‐induced breast telangiectasias (RIBT).

Methods

After informed consent, all patients were issued the Skindex‐16 and Breast‐Q Adverse Effects of Radiation HR‐QOL questionnaires prior to receiving laser treatment. Patients were treated with a 595 nm pulsed dye laser at 4‐ to 6‐week intervals, with percent telangiectasia clearance and adverse events recorded at each visit. Post‐treatment HR‐QOL questionnaires were collected after clinician‐assessed telangiectasia clearance of >50%. Median HR‐QOL scores before and after therapy were reported for individual HR‐QOL domains (Skindex‐16) and HR‐QOL totals (Skindex‐16 and Breast‐Q Adverse Effects of Radiation). Before‐ and after‐differences were calculated using the Wilcoxon Signed‐Rank Test.

Results

Twenty‐two female patients (average age 56 years) enrolled in this study. A majority (13/22, 59%) exhibited telangiectasias across the décolletage and axilla in addition to the breast. Sixteen patients reached the 50% RIBT clearance threshold during the study period, and 11 of these patients (69%) completed follow‐up HR‐QOL questionnaires. Patients showed statistically significant improvements in emotional and functional Skindex‐16 HR‐QOL domains and in overall Skindex‐16 HR‐QOL score. Breast‐Q scores also improved significantly, illustrating a decrease in specific physical and cosmetic concerns common to radiated breast skin. Common adverse events were transient post‐treatment pain and redness.

Conclusion

Breast cancer patients with RIBT presented with substantial deficits in several HR‐QOL arenas. Laser monotherapy effectively treated the appearance of radiation dermatitis in these patients and also significantly improved HR‐QOL. Lasers Surg. Med. 50:284–290, 2018. © 2017 Wiley Periodicals, Inc.
Interpolating clothoid splines with curvature continuity
Authors: Bertolazzi Enrico , Frego Marco
Published: December 2017

An efficient algorithm for the computation of a C2 interpolating clothoid spline is herein presented. The spline is obtained following an optimisation process, subject to continuity constraints. Among the 9 various targets/problems considered, there are boundary conditions, minimum length path, minimum jerk, and minimum curvature (energy). Some of these problems are solved with just a couple of Newton iterations, whereas the more complex minimisations are solved with few iterations of a nonlinear solver. The solvers are warmly started with a suitable initial guess, which is extensively discussed, making the algorithm fast. Applications of the algorithm are shown relating to fonts, path planning for human walkers, and as a tool for the time‐optimal lap on a Formula 1 circuit track.
Extensions of proper efficiency in complex space
Authors: Youness E. A. , Elbrolosy Mamdouh E.
Published: December 2017

In this paper, we extend proper efficiency concepts for a vector optimization problem in complex space. The relationships among the concepts due to Benson, Borwein, Kuhn‐Tucker, and Geoffrion have been discussed under some convexity and constraints qualification conditions. The necessary and sufficient conditions for a feasible point to be a properly efficient solution are established. The results are generalizations of the concepts of proper efficiency and their related theorems from real to complex space and complete the existing ones.
Simple and robust referencing system enables identification of dissolved‐phase xenon spectral frequencies
Authors: Antonacci Michael A. , Zhang Le , Burant Alex , McCallister Drew , Branca Rosa T.
Published: December 2017

Purpose

To assess the effect of macroscopic susceptibility gradients on the gas‐phase referenced dissolved‐phase 129Xe (DPXe) chemical shift (CS) and to establish the robustness of a water‐based referencing system for in vivo DPXe spectra.

Methods

Frequency shifts induced by spatially varying magnetic susceptibility are calculated by finite‐element analysis for the human head and chest. Their effect on traditional gas‐phase referenced DPXe CS is then assessed theoretically and experimentally. A water‐based referencing system for the DPXe resonances that uses the local water protons as reference is proposed and demonstrated in vivo in rats.

Results

Across the human brain, macroscopic susceptibility gradients can induce an apparent variation in the DPXe CS of up to 2.5 ppm. An additional frequency shift as large as 6.5 ppm can exist between DPXe and gas‐phase resonances. By using nearby water protons as reference for the DPXe CS, the effect of macroscopic susceptibility gradients is eliminated and consistent CS values are obtained in vivo, regardless of shimming conditions, region of interest analyzed, animal orientation, or lung inflation. Combining in vitro and in vivo spectroscopic measurements finally enables confident assignment of some of the DPXe peaks observed in vivo.

Conclusion

To use hyperpolarized xenon as a biological probe in tissues, the DPXe CS in specific organs/tissues must be reliably measured. When the gas‐phase is used as reference, variable CS values are obtained for DPXe resonances. Reliable peak assignments in DPXe spectra can be obtained by using local water protons as reference. Magn Reson Med 80:431–441, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Double diffusion encoding MRI for the clinic
Authors: Yang Grant , Tian Qiyuan , Leuze Christoph , Wintermark Max , McNab Jennifer A.
Published: December 2017

Purpose

The purpose of this study is to develop double diffusion encoding (DDE) MRI methods for clinical use. Microscopic diffusion anisotropy measurements from DDE promise greater specificity to changes in tissue microstructure compared with conventional diffusion tensor imaging, but implementation of DDE sequences on whole‐body MRI scanners is challenging because of the limited gradient strengths and lengthy acquisition times.

Methods

A custom single‐refocused DDE sequence was implemented on a 3T whole‐body scanner. The DDE gradient orientation scheme and sequence parameters were optimized based on a Gaussian diffusion assumption. Using an optimized 5‐min DDE acquisition, microscopic fractional anisotropy (μFA) maps were acquired for the first time in multiple sclerosis patients.

Results

Based on simulations and in vivo human measurements, six parallel and six orthogonal diffusion gradient pairs were found to be the minimum number of diffusion gradient pairs necessary to produce a rotationally invariant measurement of μFA. Simulations showed that optimal precision and accuracy of μFA measurements were obtained using b‐values between 1500 and 3000 s/mm2. The μFA maps showed improved delineation of multiple sclerosis lesions compared with conventional fractional anisotropy and distinct contrast from T2‐weighted fluid attenuated inversion recovery and T1‐weighted imaging.

Conclusion

The μFA maps can be measured using DDE in a clinical setting and may provide new opportunities for characterizing multiple sclerosis lesions and other types of tissue degeneration. Magn Reson Med 80:507–520, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Outcome and complications of adjustable continence therapy (ProACT™) after radical prostatectomy: 10 years’ experience in 143 patients
Authors: Noordhoff Toscane C. , Scheepe Jeroen R. , Blok Bertil F.M.
Published: December 2017

Aims

To evaluate our outcomes of the adjustable continence balloons ProACT™ for the treatment of male stress urinary incontinence after radical prostatectomy.

Methods

Between May 2007‐August 2016 the ProACT™ was implanted in 143 patients without a history of radiotherapy. Endpoints were patient‐reported changes in pad counts and complications. Treatment was considered successful if no pad or just one “security” pad per day sufficed, and improved if daily pad use was reduced by ≥50%.

Results

Incontinence before implantation was mild in 36 (25%), moderate in 57 (40%), and severe in 50 (35%) patients. Complications within 30 days were classified by the Clavien‐Dindo classification; eight (5.6%) grade I, three (2.1%) grade II, three (2.1%) grade IIIb, and 129 (90.2%) patients had no complication. Revision was done in 43 (30%) patients. The IPSS quality of life item improved significantly from 5.0 (IQR 4.0‐5.0) preoperative to 2.0 (IQR 1.0‐4.0) and 1.0 (IQR 0.0‐3.0) 6 and 12 months after implantation, respectively. After a median follow up of 56 months (range 28 to 79, n = 112), 72 (64%) patients were improved, including 51 (45%) patients were successful. Daily pad use decreased from 3.0 to 1.0 (67% reduction). The median outcome on the Patient Global Impression of Improvement scale was “much better,” and 97 (87%) patients perceived improvement.

Conclusions

The minimally invasive ProACT™ device showed a clear beneficial continence outcome in patients with stress urinary incontinence after radical prostatectomy. The majority of the patients were satisfied and perceived improvement ≥50% on daily pad use on the long term.
Altered macromolecular pattern and content in the aging human brain
Authors: Marjańska Małgorzata , Deelchand Dinesh K. , Hodges James S. , McCarten J. Riley , Hemmy Laura S. , Grant Andrea , Terpstra Melissa
Published: December 2017

The resonances originating from proteins underlie those of metabolites in brain 1H nuclear magnetic resonance (NMR) spectra. These resonances have different physical properties from those of metabolites, such as shorter T1 and T2 relaxation time constants. The age dependence of the macromolecular pattern and content in the human brain was investigated with a focus on adults over 66 years of age using ultrahigh‐field in vivo magnetic resonance spectroscopy. Eighteen young and 23 cognitively normal older adults were studied at 7 T. Metabolite spectra were acquired in the occipital cortex and the posterior cingulate cortex with single‐voxel stimulated echo acquisition mode (STEAM) spectroscopy in 14 young and 20 older adults. Macromolecular spectra were acquired in the occipital cortex using an inversion recovery STEAM sequence in four young and three older adults. The macromolecular pattern was apparent over the 0.5–4.5‐ppm range in the inversion recovery spectra and the 0.5–2‐ppm range in the metabolite spectra. Macromolecular content was quantified from metabolite spectra using LCModel and from inversion recovery spectra using integration. Age‐associated differences in the macromolecular pattern were apparent via both types of spectra, with the largest difference observed for the 1.7‐ and 2‐ppm macromolecular resonances. A higher macromolecular content was observed in the older adults for both brain regions. Age‐specific macromolecular spectra are needed when comparing metabolite spectra from subjects of differing ages because of age‐associated differences in macromolecular pattern. Age‐associated pattern and content differences may provide information about the aging process.
Non‐invasive diagnosis and metabolic consequences of congenital portosystemic shunts in C57BL/6 J mice
Authors: Soares Ana Francisca , Lei Hongxia
Published: December 2017

This study demonstrates the suitability of magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) for the imaging of congenital portosystemic shunts (PSS) in mice, a vascular abnormality in which mesenteric blood bypasses the liver and is instead drained directly to the systemic circulation. The non‐invasive diagnosis performed in tandem with other experimental assessments permits further characterization of liver, whole‐body and brain metabolic defects associated with PSS. Magnetic resonance measurements were performed in a 26‐cm, horizontal‐bore, 14.1‐T magnet. MRA was obtained with a three‐dimensional gradient echo sequence (GRE; in‐plane resolution, 234 × 250 × 234 μm3) using a birdcage coil. Two‐dimensional GRE MRI with high spatial resolution (in‐plane resolution, 100 × 130 μm2; slices, 30 × 0.3 mm) was performed using a surface coil. Brain‐ (dorsal hippocampus) and liver‐localized 1H magnetic resonance spectroscopy (MRS) was also performed with the surface coil. Whole‐body metabolic status was evaluated with an oral glucose tolerance test (OGTT). Both MRA and anatomical MRI allowed the identification of hepatic vessels and the diagnosis of PSS in mice. The incidence of PSS was about 10%. Hepatic lipid content was higher in PSS than in control mice (5.1 ± 2.8% versus 1.8 ± 0.6%, p = 0.02). PSS mice had higher brain glutamine concentration than controls (7.3 ± 1.0 μmol/g versus 2.7 ± 0.6 μmol/g, p < 0.0001) and, conversely, lower myo‐inositol (4.2 ± 0.6 μmol/g versus 6.0 ± 0.4 μmol/g, p < 0.0001), taurine (9.7 ± 1.2 μmol/g versus 11.0 ± 0.4 μmol/g, p < 0.01) and total choline (0.9 ± 0.1 μmol/g versus 1.2 ± 0.1 μmol/g, p < 0.001) concentrations. Fasting blood glucose and plasma insulin were lower in PSS than in control mice (4.7 ± 0.5mM versus 8.8 ± 0.6mM, p < 0.0001; and 0.04 ± 0.03 μg/L versus 0.3 ± 0.2 μg/L, p = 0.02, respectively). Glucose clearance during OGTT was delayed and less efficient in PSS mice than in controls. Thus, given the non‐negligible incidence of PSS in inbred mice, the undiagnosed presence of PSS will, importantly, have an impact on experimental outcomes, notably in studies addressing brain, liver or whole‐body metabolism.
Retrospective motion gating in cardiac MRI using a simultaneously acquired navigator
Authors: Kim Byungjai , Seo Hyunseok , Kim Dongchan , Park HyunWook
Published: December 2017

A simultaneous acquisition technique of image and navigator signals (simultaneously acquired navigator, SIMNAV) is proposed for cardiac magnetic resonance imaging (CMRI) in Cartesian coordinates. To simultaneously acquire both image and navigator signals, a conventional balanced steady‐state free precession (bSSFP) pulse sequence is modified by adding a radiofrequency (RF) pulse, which excites a supplementary slice for the navigator signal. Alternating phases of the RF pulses make it easy to separate the simultaneously acquired magnetic resonance data into image and navigator signals. The navigator signals of the proposed SIMNAV were compared with those of current gating devices and self‐gating techniques for seven healthy subjects.In vivoexperiments demonstrated that SIMNAV could provide cardiac cine images with sufficient image quality, similar to those from electrocardiogram (ECG) gating with breath‐hold. SIMNAV can be used to acquire a cardiac cine image without requiring an ECG device and breath‐hold, whilst maintaining feasible imaging time efficiency.
Assessment of the need for DCE MRI in the detection of dominant lesions in the whole gland: Correlation between histology and MRI of prostate cancer
Authors: Kozlowski Piotr , Chang Silvia D. , Jones Edward C. , Goldenberg S. Larry
Published: December 2017

The purpose of this study was to evaluate the utility of dynamic contrast‐enhanced magnetic resonance imaging (DCE MRI) in the detection of dominant prostate tumors with multi‐parametric MRI of the whole gland. Combined diffusion tensor imaging (DTI) and DCE MRI from 16 patients with biopsy‐proven prostate cancer and no previous treatment were acquired with a 3.0‐T MRI scanner prior to radical prostatectomy, and used to identify dominant tumors. MRI results were validated by whole‐mount histology. Paired t‐test and Wilcoxon test, logistic generalized linear mixed effect models and receiver operating characteristic (ROC) analyses were used for the estimation of the statistical significance of the results. In the peripheral zone (PZ), the areas under the ROC curve (ROC‐AUC) were 0.98 (sensitivity, 96%; specificity, 98%) for DTI, 0.96 (sensitivity, 92%; specificity, 97%) for DCE and 0.99 (sensitivity, 98%; specificity, 98%) for DTI + DCE. In the entire prostate, the ROC‐AUC values were 0.96 (sensitivity, 84%; specificity, 95%) for DTI, 0.87 (sensitivity, 45%; specificity, 94%) for DCE and 0.96 (sensitivity, 88%; specificity, 98%) for DTI + DCE. The increase in ROC‐AUC by the addition of DCE was not statistically significant in either PZ or the entire prostate. The results of this study have shown that DTI identified dominant tumors with high accuracy in both PZ and the entire prostate, whereas the inclusion of DCE MRI had no significant impact on the identification of either PZ or entire prostate dominant lesions. Our results suggest that the inclusion of DCE MRI may not increase the accuracy of dominant lesion detection, allowing for faster, better tolerated imaging studies.
Online scheduling with multi‐state machines
Authors: Hwang Dawsen , Jaillet Patrick
Published: December 2017

In this paper, we propose a general framework for online scheduling problems in which each machine has multiple states that lead to different processing times. For these problems, in addition to deciding how to assign jobs to machines, we also need to set the states of the machines each time they are assigned jobs. For a wide range of machine environments, job processing characteristics and constraints, and cost functions, we develop a ‐competitive deterministic online algorithm and a ‐competitive randomized online algorithm. The online weighted traveling repairman problem belongs to this general framework, and both our deterministic and randomized online algorithms lead to lower competitive ratios than the current existing ones in the literature. In addition, we include a complete proof that the online algorithm (reoptimizing the route of the repairman whenever a new request is released) is almost surely asymptotically optimal for a probabilistic version of this problem.
Adaptation and validation of the German Patient Activation Measure for adolescents with chronic conditions in transitional care: PAM® 13 for Adolescents
Authors: Bomba Franziska , Markwart Henriette , Mühlan Holger , Menrath Ingo , Ernst Gundula , Thyen Ute , Schmidt Silke
Published: December 2017

Measuring adolescent patients’ engagement in their health care is especially important in preparing for chronically ill adolescents’ transition into adult care. In this study, we aimed to create an adolescent version of the German language Patient Activation Measure (PAM‐13‐D) originally tested in in adults and psychometrically test the adapted measure (PAM® 13 for Adolescents). After linguistic and content‐related adaptations, the PAM® 13 for Adolescents was tested in a large sample of adolescents with different chronic conditions (N = 586, mean age 17.5 years, SD = 1.4) in 40 health centers. Internal consistency was assessed with Cronbach's alpha and test–retest reliability with Pearson correlation. Convergent and divergent validity were calculated with Pearson correlations between the two IE‐4 scales (internal and external Locus of Control) and the PAM® 13 for Adolescents. Known‐group validity (type 1 diabetes vs. IBD, higher vs. lower education level) was checked by Mann–Whitney‐U‐tests. The PAM® 13 for Adolescents showed good test–retest reliability (rtt = .68), internal consistency (α = .79) and demonstrated good validity. The original structure of the PAM 13‐D was replicated. Rasch analysis using the partial credit model was used to investigate the operating characteristics of the items. Rasch analysis indicated a sufficient fit of 12 of the 13 items. PAM® 13 for Adolescents is the first instrument measuring patient activation of adolescents with chronic conditions in a broad age range. Patient activation level can be used by clinicians to better plan and structure transition processes.
Can computerized cognitive training reverse the diagnosis of HIV‐associated neurocognitive disorder? A research protocol
Authors: Vance David E. , Fazeli Pariya L. , Azuero Andres , Wadley Virginia G. , Jensen Michael , Raper James L.
Published: December 2017

Nearly 50% of adults with HIV have some form of HIV‐associated neurocognitive disorder (HAND), ranging from subtle to symptoms that interfere with everyday functioning and quality of life. HAND is diagnosed when a person performs more than 1 standard deviation below his or her normative mean on standardized measures in two or more cognitive domains (e.g., attention, speed of processing, verbal memory, executive functioning). As adults age with HIV, they are more likely to develop comorbidities such as cardiovascular disease, hypertension, and insulin resistance that may further contribute to poorer cognitive functioning and HAND. Certain computerized cognitive training programs may be able to improve specific cognitive domains in those with HIV. Such programs may be effective in changing the diagnosis of HAND in cognitively vulnerable adults. In this article, we describe the design and methods of TOPS—the Training On Purpose Study. In this on‐going experimental study, 146 older adults (50+) with HAND are randomized to either: (i) an Individualized‐Targeted Cognitive Training group, or (ii) a no‐contact control group. This study targets those cognitive domains in which participants experience a deficit and trains participants with the corresponding computerized cognitive training program for that domain. An Individualized Targeted Cognitive Training approach using cognitive‐domain‐specific cognitive training programs may offer symptom relief to those individuals diagnosed with HAND, which may actually reverse this diagnosis. Given that these cognitive training programs are commercially available, this approach represents a potential paradigm shift in how HAND is considered and treated.
Genomic classifications of renal cell carcinoma: a critical step towards the future application of personalized kidney cancer care with pan‐omics precision
Authors: Hsieh James J , Le Valerie , Cao Dengfeng , Cheng Emily H , Creighton Chad J
Published: December 2017

Over the past 20 years, classifications of kidney cancer have undergone major revisions based on morphological refinements and molecular characterizations. The 2016 WHO classification of renal tumors recognizes more than ten different renal cell carcinoma (RCC) subtypes. Furthermore, the marked inter‐ and intra‐tumor heterogeneity of RCC is now well appreciated. Nevertheless, contemporary multi‐omics studies of RCC, encompassing genomics, transcriptomics, proteomics, and metabolomics, not only highlight apparent diversity but also showcase and underline commonality. Here, we wish to provide an integrated perspective concerning the future ‘functional’ classification of renal cancer by bridging gaps among morphology, biology, multi‐omics, and therapeutics. This review focuses on recent progress and elaborates the potential value of contemporary pan‐omics approaches with a special emphasis on cancer genomics unveiled through next‐generation sequencing technology, and how an integrated multi‐omics approach might impact precision‐based personalized kidney cancer care in the near future. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Numerical simulation the air jet flow field of a dual slot inset blunt die in the melt blowing nonwoven process
Authors: Zhao Bo
Published: December 2017

In this work, the air drawing model and the air jet flow field model of the dual slot inset blunt die of polypropylene polymer nonwovens fabrics in melt blowing process were established. The effect of density and specific heat capacity of polymer melt at constant pressure changing with polymer temperature on fiber diameter are studied. The air jet flow field model was solved by using the finite difference method. The computational simulation results of the distributions of the z‐components of air temperature and air velocity along the spinline during melt blowing process are in accordance with the experimental data. The air drawing model of melt blowing process was simulated by means of the numerical simulation results of the air jet flow field. The predicted fiber diameter agrees with the experimental data. The effects of processing parameters air initial velocity and air initial temperature on the fiber diameter. A higher air velocity and higher air temperature can yield the finer fibers. The results demonstrate that a higher air initial velocity and a higher air initial temperature are beneficial to the air drawing of the polymer melt and thus to reducing fiber diameter. The results show the great potential of this research for computer assisted design in melt blowing nonwoven process and technology. POLYM. ENG. SCI., 58:1817–1825, 2018. © 2017 Society of Plastics Engineers
Viscoelastic behavior and sol‐gel transition of cellulose/silk fibroin/1‐butyl‐3‐methylimidazolium chloride extended from dilute to concentrated solutions
Authors: Yao Yongbo , Yan Zhiyong , Li Zhe , Zhang Yumei , Wang Huaping
Published: December 2017

The viscoelastic behavior of cellulose/silk fibroin/1‐butyl‐3‐methylimidazolium chloride ([BMIM]Cl) extended from dilute to concentrated has been studied by rheology. When the blend ratio of cellulose/silk fibroin is 8/2 (w/w), the critical overlap (c*) and entangled concentration (ce) of the solutions are 0.5 and 2 wt% at 20°C, respectively. Moreover, the failure of Cox‐Merz at high shear rates or frequencies indicates a two‐phase structure, and the miscibility was improved with the increase of cellulose/silk fibroin concentration, as determined by the time‐temperature superposition principle and Han plot. The effect of cellulose/silk fibroin concentration on the sol‐gel transition was also studied, the gelation temperature (Tgel) can be obtained when the concentration is in the semidilute unentangled and entangled regimes. POLYM. ENG. SCI., 58:1931–1936, 2018. © 2017 Society of Plastics Engineers