bluuebunny/crossref_metadata_2025_split huggingface dataset:
MRI-Based Assessment of Lower-Extremity Muscle Volumes in Patients Before and After ACL Reconstruction
Authors: Norte Grant E. , Knaus Katherine R. , Kuenze Chris , Handsfield Geoffrey G. , Meyer Craig H. , Blemker Silvia S. , Hart Joseph M. 
Published: March 2017

Context: Study of muscle volumes in patients after anterior cruciate ligament (ACL) injury and reconstruction (ACL-R) is largely limited to cross-sectional assessment of the thigh musculature, which may inadequately describe posttraumatic and postsurgical muscle function. No studies have prospectively examined the influence of ACL injury and reconstruction on lower-extremity muscle volumes. Objective: Assess magnetic resonance imaging-derived lower-extremity muscle volumes, and quantify quadriceps strength and activation in patients following ACL injury and reconstruction. Design: Prospective case series. Setting: Research laboratory and magnetic resonance imaging facility. Patients (or Other Participants): Four patients (2 men and 2 women; age = 27.4 (7.4) y, height = 169.2 (8.1) cm, and mass = 74.3 (18.5) kg) scheduled for ACL-R. Intervention(s): Thirty-five muscle volumes were obtained from a bilateral lower-extremity magnetic resonance imaging before and after ACL-R. Main Outcome Measures: Muscle volumes expressed relative to (1) a normative database presurgery and postsurgery, (2) limb symmetry presurgery and postsurgery, and (3) percentage change presurgery to postsurgery. Quadriceps function was quantified by normalized knee extension maximal voluntary isometric contraction torque and central activation ratio. Results: Involved vastus lateralis and tibialis anterior were consistently smaller than healthy individuals (z < −1 SD) presurgery and postsurgery in all patients. Involved rectus femoris and vastus lateralis were more than 15% smaller than the contralateral limb presurgery, whereas the involved rectus femoris, gracilis, vastus medialis, vastus intermedius, and vastus lateralis muscle volumes exceeded 20% asymmetry postoperatively. Involved gracilis and semitendinosus atrophied more than 30% from presurgery to postsurgery. Involved maximal voluntary isometric contraction torque and central activation ratio increased by 12.7% and 12.5%, respectively, yet strength remained 33.2% asymmetric postsurgery. Conclusions: Adaptations in lower-extremity muscle volumes are present following ACL injury and reconstruction. Anterior thigh and shank muscles were smaller than healthy individuals, and large asymmetries in quadriceps volumes were observed presurgery and postsurgery. Selective atrophy of the semitendinosus and gracilis occurred following surgery. Volumetric deficits of the quadriceps musculature may exist despite improvements in muscle strength and activation.
Cross-Validation of Two Accelerometers for Assessment of Physical Activity and Sedentary Time in Preschool Children
Authors: Alhassan Sofiya , Sirard John R. , Kurdziel Laura B. F. , Merrigan Samantha , Greever Cory , Spencer Rebecca M. C. 
Published: March 2017

Purpose:The purpose of this study was to cross-validate previously developed Actiwatch (AW; Ekblom et al. 2012) and AcitGraph (AG; Sirard et al. 2005; AG-P, Pate et al. 2006) cut-point equations to categorize free-living physical activity (PA) of preschoolers using direct observation (DO) as the criterion measure. A secondary aim was to compare output from the AW and the AG from previously developed equations.Methods:Participants’ (n = 33; age = 4.4 ± 0.8 yrs; females, n=12) PA was directly observed for three 10-min periods during the preschool-day while wearing the AW (nondominant wrist) and AG (waist). Device specific cut-points were used to reduce the AW-E (Ekblom et al. 2012) and AG (AG-S, Sirard et al. 2005; AG-P, Pate et al. 2006) data into intensity categories. Spearman correlations (rsp) and agreement statistics were used to assess associations between the DO intensity categories and device data. Mixed model regression was used to identify differences in times spent in activity intensity categories.Results:There was a significant correlation between AW and AG output across all data (rsp = 0.41, p < .0001) and both were associated with the DO intensity categories (AW: rsp = 0.47, AG: rsp = 0.47; p < .001). At the individual level, all devices demonstrated relatively low sensitivity but higher specificity. At the group level, AW-E and AG-P provided similar estimates of time spent in moderate-to-vigorous PA (MVPA, AW-E: 4.7 ± 4.1, AG-P: 4.4 ± 3.3), compared with DO (5.1 ± 3.5). Conclusion: The AW-E and AG-P estimated times spent in MVPA were similar to DO, but the weak agreement statistics indicate that neither device cut-point equations provided accurate estimates at the individual level.
Characterizing the Antimicrobial Activity of
N
2
,
N
4
-Disubstituted Quinazoline-2,4-Diamines toward Multidrug-Resistant Acinetobacter baumannii
Authors: Fleeman Renee , Van Horn Kurt S. , Barber Megan M. , Burda Whittney N. , Flanigan David L. , Manetsch Roman , Shaw Lindsey N. 
Published: March 2017

ABSTRACT

We previously reported a series of
N
2
,
N
4
-disubstituted quinazoline-2,4-diamines as dihydrofolate reductase inhibitors with potent
in vitro
and
in vivo
antibacterial activity against methicillin-resistant
Staphylococcus aureus
(MRSA) strains. In this work, we extended our previous study to the Gram-negative pathogen
Acinetobacter baumannii
. We determined that optimized
N
2
,
N
4
-disubstituted quinazoline-2,4-diamines are strongly antibacterial against multidrug-resistant
A. baumannii
strains when the 6-position is replaced with a halide or an alkyl substituent. Such agents display potent antibacterial activity, with MICs as low as 0.5 μM, while proving to be strongly bactericidal. Interestingly, these compounds also possess the potential for antibiofilm activity, eradicating 90% of cells within a biofilm at or near MICs. Using serial passage assays, we observed a limited capacity for the development of resistance toward these molecules (4-fold increase in MIC) compared to existing folic acid synthesis inhibitors, such as trimethoprim (64-fold increase) and sulfamethoxazole (128-fold increase). We also identified limited toxicity toward human cells, with 50% lethal doses (LD
50
s) of ≤23 μM for lead agents 4 and 5. Finally, we demonstrated that our lead agents have excellent
in vivo
efficacy, with lead agent 5 proving more efficacious than tigecycline in a murine model of
A. baumannii
infection (90% survival versus 66%), despite being used at a lower dose (2 versus 30 mg kg
−1
). Together, our results demonstrate that
N
2
,
N
4
-disubstituted quinazoline-2,4-diamines have strong antimicrobial and antibiofilm activities against both Gram-positive organisms and Gram-negative pathogens, suggesting strong potential for their development as antibacterial agents.
Are Antimalarial Hybrid Molecules a Close Reality or a Distant Dream?
Authors: Agarwal Drishti , Gupta Rinkoo D. , Awasthi Satish K. 
Published: March 2017

ABSTRACTEmergence of drug-resistantPlasmodium falciparumstrains has led to a situation of haste in the scientific and pharmaceutical communities. Hence, all their efforts are redirected toward finding alternative chemotherapeutic agents that are capable of combating multidrug-resistant parasite strains. In light of this situation, scientists have come up with the concept of hybridization of two or more active pharmacophores into a single chemical entity, resulting in “antimalarial hybrids.” The approach has been applied widely for generation of lead compounds against deadly diseases such as cancer and AIDS, with a proven potential for use as novel drugs, but is comparatively new in the sphere of antimalarial drug discovery. A sudden surge has been evidenced in the number of studies on the design and synthesis of hybrids for treating malaria and may be regarded as proof of their potential advantages over artemisinin-based combination therapy (ACT). However, it is evident from recent studies that most of the potential advantages of antimalarial hybrids, such as lower toxicity, better pharmacokinetics, and easier formulation, have yet to be realized. A number of questions left unaddressed at present need to be answered before this approach can progress to the late stages of clinical development and prove their worth in the clinic. To the best of our knowledge, this compilation is the first attempt to shed light on the shortcomings that are surfacing as more and more studies on molecular hybridization of the active pharmacophores of known antimalarials are being published.
Staphylococcus aureus Survives in Cystic Fibrosis Macrophages, Forming a Reservoir for Chronic Pneumonia
Authors: Li Cao , Wu Yuqing , Riehle Andrea , Ma Jie , Kamler Markus , Gulbins Erich , Grassmé Heike 
Published: March 2017

ABSTRACT

Staphylococcus aureus
plays an important role in sepsis, pneumonia, wound infections, and cystic fibrosis (CF), which is caused by mutations of the cystic fibrosis transmembrane conductance regulator (
Cftr
). Pulmonary
S. aureus
infections in CF often occur very early and prior to colonization with other pathogens, in particular
Pseudomonas aeruginosa
. Here, we demonstrate that CF mice are highly susceptible to pulmonary infections with
S. aureus
and fail to clear the pathogen during infection.
S. aureus
is internalized by
Cftr
-deficient macrophages in the lung, but these macrophages are unable to kill intracellular bacteria. This failure might be caused by a defect in the fusion of phagosomes with lysosomes, while this process occurs rapidly in wild-type macrophages and serves to kill intracellular pathogens. Transplantation of infected
Cftr
-deficient alveolar macrophages into the lungs of noninfected CF mice is sufficient to induce pneumonia. This suggests that intracellular survival of
S. aureus
in macrophages may allow the pathogen to chronically infect CF lungs.
SgrT, a Small Protein That Packs a Sweet Punch
Authors: Raina Medha , Storz Gisela 
Published: March 2017

ABSTRACT

The SgrS small RNA (sRNA) has been shown to protect against elevated levels of glucose phosphate by regulating the stability and translation of mRNAs encoding proteins involved in sugar transport and catabolism. The sRNA also was known to encode a protective 43-amino-acid protein, SgrT, but little was known about its mechanism of action. Lloyd et al. (J Bacteriol 199:e00869-16, 2017,
https://doi.org/10.1128/JB.00869-16
) use cell biological and genetic approaches to demonstrate that the small protein interacts with the PtsG importer to block glucose transport by this phosphotransferase system and promote utilization of nonpreferred carbon sources to maintain growth during glucose-phosphate stress.
Are patients with cancer with sepsis and bacteraemia at a higher risk of mortality? A retrospective chart review of patients presenting to a tertiary care centre in Lebanon
Authors: Abou Dagher Gilbert , El Khuri Christopher , Chehadeh Ahel Al-Hajj , Chami Ali , Bachir Rana , Zebian Dina , Bou Chebl Ralphe 
Published: March 2017

ObjectiveMost sepsis studies have looked at the general population. The aim of this study is to report on the characteristics, treatment and hospital mortality of patients with cancer diagnosed with sepsis or septic shock.SettingA single-centre retrospective study at a tertiary care centre looking at patients with cancer who presented to our tertiary hospital with sepsis, septic shock or bacteraemia between 2010 and 2015.Participants176 patients with cancer were compared with 176 cancer-free controls.Primary and secondary outcomesThe primary outcome of this study was the in hospital mortality in both cohorts. Secondary outcomes included patient demographics, emergency department (ED) vital signs and parameters of resuscitation along with laboratory work.ResultsA total of 352 patients were analysed. The mean age at presentation for the cancer group was 65.39±15.04 years, whereas the mean age for the control group was 74.68±14.04 years (p<0.001). In the cancer cohort the respiratory system was the most common site of infection (37.5%) followed by the urinary system (26.7%), while in the cancer-free arm, the urinary system was the most common site of infection (40.9%). intravenous fluid replacement for the first 24 hours was higher in the cancer cohort. ED, intensive care unit and general practice unit length of stay were comparable in both the groups. 95 (54%) patients with cancer died compared with 75 (42.6%) in the cancer-free group. The 28-day hospital mortality in the cancer cohort was 87 (49.4%) vs 46 (26.1%) in the cancer-free cohort (p=0.009). Patients with cancer had a 2.320 (CI 95% 1.225 to 4.395, p=0.010) odds of dying compared with patients without cancer in the setting of sepsis.ConclusionsThis is the first study looking at an in-depth analysis of sepsis in the specific oncology population. Despite aggressive care, patients with cancer have higher hospital mortality than their cancer-free counterparts while adjusting for all other variables.
Health risk of inhalation exposure to sub-10 µm particulate matter and gaseous pollutants in an urban-industrial area in South Africa: an ecological study
Authors: Morakinyo Oyewale Mayowa , Adebowale Ayo Stephen , Mokgobu Matlou Ingrid , Mukhola Murembiwa Stanley 
Published: March 2017

ObjectiveTo assess the health risks associated with exposure to particulate matter (PM10), sulphur dioxide (SO2), nitrogen dioxide (NO2), carbon monoxide (CO) and ozone (O3).DesignThe study is an ecological study that used the year 2014 hourly ambient pollution data.SettingThe study was conducted in an industrial area located in Pretoria West, South Africa. The area accommodates a coal-fired power station, metallurgical industries such as a coke plant and a manganese smelter.Data and methodEstimate of possible health risks from exposure to airborne PM10, SO2, NO2, CO and O3was performed using the US Environmental Protection Agency human health risk assessment framework. A scenario-assessment approach where normal (average exposure) and worst-case (continuous exposure) scenarios were developed for intermediate (24-hour) and chronic (annual) exposure periods for different exposure groups (infants, children, adults). The normal acute (1-hour) exposure to these pollutants was also determined.Outcome measuresPresence or absence of adverse health effects from exposure to airborne pollutants.ResultsAverage annual ambient concentration of PM10, NO2and SO2recorded was 48.3±43.4, 11.50±11.6 and 18.68±25.4 µg/m3, respectively, whereas the South African National Ambient Air Quality recommended 40, 40 and 50 µg/m3for PM10, NO2and SO2, respectively. Exposure to an hour's concentration of NO2, SO2, CO and O3, an 8-hour concentration of CO and O3, and a 24-hour concentration of PM10, NO2and SO2will not likely produce adverse effects to sensitive exposed groups. However, infants and children, rather than adults, are more likely to be affected. Moreover, for chronic annual exposure, PM10, NO2and SO2posed a health risk to sensitive individuals, with the severity of risk varying across exposed groups.ConclusionsLong-term chronic exposure to airborne PM10, NO2and SO2pollutants may result in health risks among the study population.
Admission hyperglycemia and outcomes in large vessel occlusion strokes treated with mechanical thrombectomy
Authors: Goyal Nitin , Tsivgoulis Georgios , Pandhi Abhi , Dillard Kira , Katsanos Aristeidis H , Magoufis Georgios , Chang Jason J , Zand Ramin , Hoit Daniel , Safouris Apostolos , Choudhri Asim , Alexandrov Anne W , Alexandrov Andrei V , Arthur Adam S , Elijovich Lucas 
Published: March 2017

Background and purposeHigher admission serum glucose levels have been associated with poor outcomes in patients with acute ischemic stroke (AIS) treated with IV thrombolysis. We sought to evaluate the association of admission serum glucose with early outcomes of patients with emergent large vessel occlusion (ELVO) treated with mechanical thrombectomy (MT).MethodsConsecutive AIS patients due to ELVO treated with MT in three tertiary stroke centers were evaluated. The following outcomes were documented using standard definitions: symptomatic intracranial hemorrhage (sICH), complete reperfusion, mortality, functional independence (modified Rankin Scale (mRS) score of 0–2), and functional improvement (shift in mRS score) at 3 months. The association of admission serum glucose and admission hyperglycemia (>140 mg/dL) with outcomes was evaluated using univariable and multivariable binary and ordinal logistic regression models.Results231 AIS patients with ELVO (mean age 62±14 years, 51% men, median admission National Institute of Health Stroke Scale score 16 points (IQR 12–21), median admission serum glucose 125 mg/dL (IQR 104–162)) were treated with MT. Admission hyperglycemia was associated with a lower likelihood of functional improvement (common OR 0.53; 95% CI 0.31 to 0.97; p=0.027) and higher odds of 3 month mortality (OR 2.76; 95% CI 1.40 to 5.44; p=0.004) in multivariable analyses adjusting for potential confounders. A 10 mg/dL increase in admission blood glucose was associated with a higher likelihood of sICH (OR 1.07; 95% CI 1.01 to 1.13; p=0.033) and 3 month mortality (OR 1.07; 95% CI 1.02 to 1.12; p=0.004) in multivariable models. There was no association between admission serum glucose or hyperglycemia and complete reperfusion.ConclusionsHigher admission serum glucose and admission hyperglycemia are independent predictors of adverse outcomes in ELVO patients treated with MT.
CLASSIFICATION OF TWO- AND THREE-FACTOR TIME-HOMOGENEOUS SEPARABLE LMMs
Authors: GOGALA JAKA , KENNEDY JOANNE E. 
Published: March 2017

The flexibility of parametrizations of the LIBOR market model (LMM) comes at a cost, namely the LMM is high-dimensional, which makes it cumbersome to use when pricing derivatives with early exercise features. One way to overcome this issue for short- and medium-term time horizons is by imposing the separability condition on the volatility functions and approximating the model using a single time-step approximation. In this paper, we examine the flexibility of separable LMMs under the relaxed assumption that the driving Brownian motions can be correlated. In particular, we are interested in how the separability condition interacts with time-homogeneity, a desirable property of a LMM. We show that the two concepts can be related using a Levi-Civitá equation and provide a characterization of two- and three-factor separable and time-homogeneous LMMs and show that they are of practical interest. The results presented in this paper are also applicable to local-volatility LMMs. These separable volatility structures can be used for the driver of a two- or three-dimensional Markov-functional model — in which case no (single time-step) approximation is needed and the resultant model is both time-homogeneous and arbitrage-free.
Population activity statistics dissect subthreshold and spiking variability in V1
Authors: Bányai Mihály , Koman Zsombor , Orbán Gergő 
Published: March 2017

Response variability, as measured by fluctuating responses upon repeated performance of trials, is a major component of neural responses, and its characterization is key to interpret high dimensional population recordings. Response variability and covariability display predictable changes upon changes in stimulus and cognitive or behavioral state, providing an opportunity to test the predictive power of models of neural variability. Still, there is little agreement on which model to use as a building block for population-level analyses, and models of variability are often treated as a subject of choice. We investigate two competing models, the doubly stochastic Poisson (DSP) model assuming stochasticity at spike generation, and the rectified Gaussian (RG) model tracing variability back to membrane potential variance, to analyze stimulus-dependent modulation of both single-neuron and pairwise response statistics. Using a pair of model neurons, we demonstrate that the two models predict similar single-cell statistics. However, DSP and RG models have contradicting predictions on the joint statistics of spiking responses. To test the models against data, we build a population model to simulate stimulus change-related modulations in pairwise response statistics. We use single-unit data from the primary visual cortex (V1) of monkeys to show that while model predictions for variance are qualitatively similar to experimental data, only the RG model's predictions are compatible with joint statistics. These results suggest that models using Poisson-like variability might fail to capture important properties of response statistics. We argue that membrane potential-level modeling of stochasticity provides an efficient strategy to model correlations. NEW & NOTEWORTHY Neural variability and covariability are puzzling aspects of cortical computations. For efficient decoding and prediction, models of information encoding in neural populations hinge on an appropriate model of variability. Our work shows that stimulus-dependent changes in pairwise but not in single-cell statistics can differentiate between two widely used models of neuronal variability. Contrasting model predictions with neuronal data provides hints on the noise sources in spiking and provides constraints on statistical models of population activity.
Low Speed Estimation in Sensorless Direct Torque Controlled Induction Motor Drive Using Extended Kalman Filter
Authors: R Mini , C Saranya , Satheesh B. Hariram , M.N. Dinesh 
Published: March 2017

Sensorless Direct Torque Control (DTC) is a powerful control scheme for high performance control of induction motor (IM) drives, which provides very quick dynamic response with simple structure and a decoupled control of torque and flux. The performance of the DTC drive depends greatly on the accuracy of the estimated flux components, torque and speed, using monitored stator voltages and currents. Low speed estimation is a great challenge because of the presence of transient offset, drift and domination of ohmic voltage drop.Extended Kalman filter (EKF) is a non linear adaptive filter which performs the process of finding the best estimate from the noisy data based on state space techniques and recursive algorithm. This paper mainly focuses on the accurate estimation of speed ranging from very low speed to rated speed using the equation of motion. A new state space model of the IM is developed for estimation in EKF, with load torque as an input variable and not as an estimated quantity which is the case in most previous studies. The developed algorithm is validated using MATLAB-Simulink platform for speeds ranging from low speed to rated speed at rated torque and at various torque conditions. An exhaustive analysis is carried out to validate the performance of DTC Induction motor drive especially at the low speeds. The results are promising for accurate estimation of speed ranging from low speed to rated speed using EKF.