bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crop type and altitude are the main drivers of species composition of arable weed vegetation in Tajikistan
Authors: Nowak A , Nowak S , Nobis M , Nobis A 
Published: June 2015

SummaryThe influence of broad‐scale environmental factors on the species composition of segetal weed communities in Tajikistan was investigated. The research was conducted throughout the country, analysing plots of root crops as well as cereals from all phytogeographical regions of Tajikistan, with the exception of the eastern Pamir. The study was based on 440 phytosociological relevées sampled between 2009 and 2013 and analysed using direct and indirect ordinations. A set of environmental variables was obtained for each plot: altitude, mean annual precipitation, mean annual temperature, pH, crop type, longitude, latitude and date of sampling (seasonality). Crop type was the major factor determining species composition, which was related to the different farming practices in roots and cereals. Major changes in weed species composition were also driven by altitude and correlated temperatures. The seasonality of weed communities also had a considerable effect on weed community structure. Samples from spring differed significantly from samples from summer and late summer. Only longitude and soil pH were found to be insignificant. The complete set of environmental variables used in a canonical correspondence analysis explained 8.3% of the species variation in sampled plots. The study showed that despite the very diverse climatic conditions and low intensity of agriculture in Tajikistan, agrocoenoses respond mainly to the type of cultivation practised in arable land.
Wound repair during arm regeneration in the red starfish Echinaster sepositus
Authors: Ben Khadra Yousra , Ferrario Cinzia , Di Benedetto Cristiano , Said Khaled , Bonasoro Francesco , Candia Carnevali M. Daniela , Sugni Michela 
Published: June 2015

ABSTRACTStarfish can regenerate entire arms following their loss by both autotomic and traumatic amputation. Although the overall regenerative process has been studied several times in different asteroid species, there is still a considerable gap of knowledge as far as the detailed aspects of the repair phase at tissue and cellular level are concerned, particularly in post‐traumatic regeneration. The present work is focused on the arm regeneration model in the Mediterranean red starfish Echinaster sepositus; to describe the early cellular mechanisms of arm regeneration following traumatic amputation, different microscopy techniques were employed. In E. sepositus, the repair phase was characterized by prompt wound healing by a syncytial network of phagocytes and re‐epithelialisation followed by a localized subepidermal oedematous area formation. Scattered and apparently undifferentiated cells, intermixed with numerous phagocytes, were frequently found in the wound area during these first stages of regeneration and extensive dedifferentiation phenomena were seen at the level of the stump, particularly in the muscle bundles. A true localized blastema did not form. Our results confirm that regeneration in asteroids mainly relies on morphallactic processes, consisting in extensive rearrangement of the existing tissues which contribute to the new tissues through cell dedifferentiation, redifferentiation, and/or migration.
SDF‐1 liposomes promote sustained cell proliferation in mouse diabetic wounds
Authors: Olekson Melissa A. Przyborowski , Faulknor Renea , Bandekar Amey , Sempkowski Michelle , Hsia Henry C. , Berthiaume François 
Published: June 2015

ABSTRACTChronic skin wounds are a common complication of diabetes. When standard wound care fails to heal such wounds, a promising approach consists of using decellularized matrices and other porous scaffold materials to promote the restoration of skin. Proper revascularization is critical for the efficacy of such materials in regenerative medicine. Stromal cell‐derived factor‐1 (SDF‐1) is a chemokine known to play a key role for angiogenesis in ischemic tissues. Herein we developed nanosized SDF‐1 liposomes, which were then incorporated into decellularized dermis scaffolds used for skin wound healing applications. SDF‐1 peptide associated with liposomes with an efficiency of 80%, and liposomes were easily dispersed throughout the acellular dermis. Acellular dermis spiked with SDF‐1 liposomes exhibited more persistent cell proliferation in the dermis, especially in CD31+ areas, compared to acellular dermis spiked with free SDF‐1, which resulted in increased improved wound closure at day 21, and increased granulation tissue thickness at day 28. SDF‐1 liposomes may increase the performance of a variety of decellularized matrices used in tissue engineering.
The role of nitric oxide in passive leg movement‐induced vasodilatation with age: insight from alterations in femoral perfusion pressure
Authors: Groot H. Jonathan , Trinity Joel D. , Layec Gwenael , Rossman Matthew J. , Ives Stephen J. , Morgan David E. , Bledsoe Amber , Richardson Russell S. 
Published: June 2015

Key points
The passive leg movement (PLM) model is a novel approach to assess vascular function.
Increasing femoral perfusion pressure (FPP) by moving from the supine to the upright‐seated posture augments the vasodilatory response to PLM in the young, with no effect in the old, but whether this augmented vasodilatation is nitric oxide (NO) dependent is unknown.
Using an intra‐arterial infusion of NG‐monomethyl‐L‐arginine (L‐NMMA) to inhibit nitric oxide synthase (NOS), the posture‐induced increases in the PLM responses in the young were nearly ablated, with no effect of NOS inhibition in the old.
Therefore, PLM in combination with alterations in posture can be used to determine changes in NO‐mediated vasodilatation with age, and thus, may be a clinically useful tool for assessing NO bioavailability across the human lifespan.
AbstractWe sought to better understand the contribution of nitric oxide (NO) to passive leg movement (PLM)‐induced vasodilatation with age, with and without a posture‐induced increase in femoral perfusion pressure (FPP). PLM was performed in eight young (24 ± 1 years) and eight old (74 ± 3 years) healthy males, with and without NO synthase inhibition via intra‐arterial infusion of NG‐monomethyl‐L‐arginine (L‐NMMA) into the common femoral artery in both the supine and upright‐seated posture. Central and peripheral haemodynamic responses were determined second‐by‐second with finger photoplethysmography and Doppler ultrasound, respectively. PLM‐induced increases in heart rate, stroke volume, cardiac output and reductions in mean arterial pressure were similar between age groups and conditions. In the young, L‐NMMA attenuated the peak change in leg vascular conductance (ΔLVCpeak) in both the supine (control: 7.4 ± 0.9; L‐NMMA: 5.2 ± 1.1 ml min−1 mmHg−1, P < 0.05) and upright‐seated (control: 12.3 ± 2.0; L‐NMMA: 6.4 ± 1.0 ml min−1 mmHg−1, P < 0.05) posture, with no significant change in the old (supine control: 4.2 ± 1.3; supine L‐NMMA: 3.4 ± 0.8; upright‐seated control: 4.5 ± 0.8; upright‐seated L‐NMMA: 3.4 ± 0.8 ml min−1 mmHg−1, P > 0.05). Increased FPP augmented the ΔLVCpeak in the young control condition only (P < 0.05). In the upright‐seated posture, NOS inhibition attenuated the FPP‐induced augmentation of rapid vasodilatation in the young (control: 1.25 ± 0.23; L‐NMMA: 0.74 ± 0.11 ml min−1 mmHg−1 s−1; P < 0.05), but not the old (control: 0.37 ± 0.07; L‐NMMA: 0.25 ± 0.07 ml ml min−1 mmHg−1 s−1; P > 0.05). These data reveal that greater FPP increases the role of NO in PLM‐induced vasodilatation in the young, but not the old, due to reduced NO bioavailability with age. Therefore, PLM involving alterations in posture may be useful to determine changes in NO bioavailability with age.
Performance of today's dual energy CT and future multi energy CT in virtual non‐contrast imaging and in iodine quantification: A simulation study
Authors: Faby Sebastian , Kuchenbecker Stefan , Sawall Stefan , Simons David , Schlemmer Heinz‐Peter , Lell Michael , Kachelrieß Marc 
Published: June 2015

Purpose:To study the performance of different dual energy computed tomography (DECT) techniques, which are available today, and future multi energy CT (MECT) employing novel photon counting detectors in an image‐based material decomposition task.Methods:The material decomposition performance of different energy‐resolved CT acquisition techniques is assessed and compared in a simulation study of virtual non‐contrast imaging and iodine quantification. The material‐specific images are obtained via a statistically optimal image‐based material decomposition. A projection‐based maximum likelihood approach was used for comparison with the authors’ image‐based method. The different dedicated dual energy CT techniques are simulated employing realistic noise models and x‐ray spectra. The authors compare dual source DECT with fast kV switching DECT and the dual layer sandwich detector DECT approach. Subsequent scanning and a subtraction method are studied as well. Further, the authors benchmark future MECT with novel photon counting detectors in a dedicated DECT application against the performance of today's DECT using a realistic model. Additionally, possible dual source concepts employing photon counting detectors are studied.Results:The DECT comparison study shows that dual source DECT has the best performance, followed by the fast kV switching technique and the sandwich detector approach. Comparing DECT with future MECT, the authors found noticeable material image quality improvements for an ideal photon counting detector; however, a realistic detector model with multiple energy bins predicts a performance on the level of dual source DECT at 100 kV/Sn 140 kV. Employing photon counting detectors in dual source concepts can improve the performance again above the level of a single realistic photon counting detector and also above the level of dual source DECT.Conclusions:Substantial differences in the performance of today's DECT approaches were found for the application of virtual non‐contrast and iodine imaging. Future MECT with realistic photon counting detectors currently can only perform comparably to dual source DECT at 100 kV/Sn 140 kV. Dual source concepts with photon counting detectors could be a solution to this problem, promising a better performance.
Oral Presence of Carbohydrate and Caffeine in Chewing Gum: Independent and Combined Effects on Endurance Cycling Performance
Authors: Oberlin-Brown Katherine T. , Siegel Rodney , Kilding Andrew E. , Laursen Paul B. 
Published: June 2015

The oral presence of carbohydrate (CHO) and caffeine (CAF) may independently enhance exercise performance, but their influence on performance during prolonged exercise is less known.Aim:To determine the independent and combined effects of CHO and CAF administered in chewing gum during a cycling time trial (TT) after prolonged exercise.Method:Eleven male cyclists (32.2 ± 7.5 y, 74.3 ± 6.8 kg, 60.2 ± 4.0 mL · kg–1 · min–1 V˙O2peak) performed 4 experimental trials consisting of 90-min constant-load cycling at 80% of their second ventilatory threshold (207 ± 30 W), followed immediately by a 20-km TT. Under double-blinded conditions, cyclists received placebo (PLA), CHO, CAF, or a combined CHO+CAF chewing gum at 0-, 5-, 10-, and 15-km points of the TT.Results:Overall TT performance was similar across experimental and PLA trials (%mean difference ± 90%CL 0.2% ± 2.0%, 0.4% ± 2.2%, 0.1% ± 1.8% for CHO, CAF, and CHO+CAF). Compared with PLA, mean power output tended to be higher in the first 2 quarters of the TT with CHO (1.6% ± 3.1% and 0.8% ± 2.0%) and was substantially improved in the last 2 quarters during CAF and CHO+CAF trials (4.2% ± 3.0% and 2.0% ± 1.8%). There were no differences in average heart rate (ES <0.2) and only small changes in blood glucose (ES 0.2), which were unrelated to performance. Blood lactate was substantially higher post-TT for CAF and CHO+CAF (ES >0.6).Conclusion:After prolonged constant-load cycling, the oral presence of CHO and CAF in chewing gum, independently or in combination, did not improve overall performance but did influence pacing.
siRNA Screening Identifies the Host Hexokinase 2 (HK2) Gene as an Important Hypoxia-Inducible Transcription Factor 1 (HIF-1) Target Gene in Toxoplasma gondii-Infected Cells
Authors: Menendez Matthew T. , Teygong Crystal , Wade Kristin , Florimond Celia , Blader Ira J. 
Published: June 2015

ABSTRACT

Although it is established that oxygen availability regulates cellular metabolism and growth, little is known regarding how intracellular pathogens use host factors to grow at physiological oxygen levels. Therefore, large-scale human small interfering RNA screening was performed to identify host genes important for growth of the intracellular protozoan parasite
Toxoplasma gondii
at tissue oxygen tensions. Among the genes identified by this screen, we focused on the hexokinase 2 (HK2) gene because its expression is regulated by hypoxia-inducible transcription factor 1 (HIF-1), which is important for
Toxoplasma
growth.
Toxoplasma
increases host HK2 transcript and protein levels in a HIF-1-dependent manner. In addition, parasite growth at 3% oxygen is restored in HIF-1-deficient cells transfected with HK2 expression plasmids. Both HIF-1 activation and HK2 expression were accompanied by increases in host glycolytic flux, suggesting that enhanced HK2 expression in parasite-infected cells is functionally significant. Parasite dependence on host HK2 and HIF-1 expression is not restricted to transformed cell lines, as both are required for parasite growth in nontransformed C2C12 myoblasts and HK2 is upregulated
in vivo
following infection. While HK2 is normally associated with the cytoplasmic face of the outer mitochondrial membrane at physiological O
2
levels, HK2 relocalizes to the host cytoplasm following infection, a process that is required for parasite growth at 3% oxygen. Taken together, our findings show that HIF-1-dependent expression and relocalization of HK2 represent a novel mechanism by which
Toxoplasma
establishes its replicative niche at tissue oxygen tensions.

IMPORTANCE
Little is known regarding how the host cell contributes to the survival of the intracellular parasite
Toxoplasma gondii
at oxygen levels that mimic those found in tissues. Our previous work showed that
Toxoplasma
activates the expression of an oxygen-regulated transcription factor that is required for growth. Here, we report that
Toxoplasma
regulates the abundance and activity of a key host metabolic enzyme, hexokinase 2, by activating HIF-1 and by promoting dissociation of hexokinase 2 from the mitochondrial membrane. Collectively, our data reveal HIF-1/hexokinase 2 as a novel target for an intracellular pathogen that acts by reprograming the host cell's metabolism to create an environment conducive for parasite replication at physiological oxygen levels.
Functional Analysis of the Human Antibody Response to Meningococcal Factor H Binding Protein
Authors: Beernink Peter T. , Giuntini Serena , Costa Isabella , Lucas Alexander H. , Granoff Dan M. 
Published: June 2015

ABSTRACTTwo licensed serogroup B meningococcal vaccines contain factor H binding protein (FHbp). The antigen specifically binds human FH, which downregulates complement. In wild-type mice whose mouse FH does not bind to FHbp vaccines, the serum anti-FHbp antibody response inhibited binding of human FH to FHbp. The inhibition was important for eliciting broad anti-FHbp serum bactericidal activity. In human FH transgenic mice and some nonhuman primates, FHbp was able to form a complex with FH and FHbp vaccination elicited anti-FHbp antibodies that did not inhibit FH binding. To investigate the human anti-FHbp repertoire, we cloned immunoglobulin heavy- and light-chain-variable-region genes of individual B cells from three adults immunized with FHbp vaccines and generated 10 sequence-distinct native anti-FHbp antibody fragments (Fabs). All 10 Fabs bound to live meningococci; only 1 slightly inhibited binding of human FH, while 4 enhanced FH binding. Affinity-purified anti-FHbp antibody from serum of a fourth immunized adult also enhanced binding of human FH to live meningococcal bacteria. Despite the bound FH, the affinity-purified serum anti-FHbp antibodies elicited human complement-mediated bactericidal activity that was amplified by the alternative pathway. The lack of FH inhibition by the human anti-FHbp Fabs and serum antibodies suggests that binding of human FH to the vaccine antigen skews the anti-FHbp antibody repertoire to epitopes outside the FH-binding site. Mutant FHbp vaccines with decreased FH binding may represent a means to redirect the human antibody repertoire to epitopes within the FH binding site, which can inhibit FH binding and, potentially, increase safety and protective activity.IMPORTANCETwo meningococcal vaccines contain factor H binding protein (FHbp). Immunized mice whose mouse factor H (FH) does not bind to FHbp develop serum anti-FHbp antibodies that block binding of human FH to the bacteria. With less bound FH, the bacteria become more susceptible to complement killing. To investigate human responses, we isolated 10 recombinant anti-FHbp antibody fragments (Fabs) from immune cells of three immunized adults. One slightly inhibited binding of FH to the bacteria, and four enhanced FH binding. Purified serum anti-FHbp antibodies from a fourth immunized adult also enhanced FH binding. Although bound FH would be expected to block the alternative pathway, the human anti-FHbp antibodies retained bactericidal activity and the ability to activate the alternative pathway. Mutant FHbp vaccines with decreased binding to human FH may redirect the human antibody repertoire to epitopes within the FH binding site that inhibit FH binding, which are expected to increase protective activity.
Effects of Transcutaneous Electrical Nerve Stimulation on Rats with the Third Lumbar Vertebrae Transverse Process Syndrome
Authors: Li Huan , Shang Xiao-Jun , Dong Qi-Rong 
Published: June 2015

Objective To investigate the analgesic and anti-inflammatory effects of transcutaneous electrical nerve stimulation (TENS) at local or distant acupuncture points in a rat model of the third lumbar vertebrae transverse process syndrome. Methods Forty Sprague–Dawley rats were randomly divided into control, model, model plus local acupuncture point stimulation at BL23 (model+LAS) and model plus distant acupuncture point stimulation at ST36 (model+DAS) groups. All rats except controls underwent surgical third lumbar vertebrae transverse process syndrome modelling on day 2. Thereafter, rats in the model+LAS and model+DAS groups were treated daily with TENS for a total of six treatments (2/100 Hz, 30 min/day) from day 16 to day 29. Thermal pain thresholds were measured once a week during treatment and were continued until day 57, when local muscle tissue was sampled for RT-PCR and histopathological examination after haematoxylin and eosin staining. mRNA expression of interleukin-1 β (IL-1β), tumour necrosis factor-α (TNF-α) and inducible nitric oxide synthase (iNOS) was determined. Results Thermal pain thresholds of all model rats decreased relative to the control group. Both LAS and DAS significantly increased the thermal pain threshold at all but one point during the treatment period. Histopathological assessment revealed that the local muscle tissues around the third lumbar vertebrae transverse process recovered to some degree in both the model+LAS and model+DAS groups; however, LAS appeared to have a greater effect. mRNA expression of IL-1β, TNF-α and iNOS in the local muscle tissues was increased after modelling and attenuated in both model+LAS and model+DAS groups. The beneficial effect was greater after LAS than after DAS. Conclusions TENS at both local (BL23) and distant (ST36) acupuncture points had a pain-relieving effect in rats with the third lumbar vertebrae transverse process syndrome, and LAS appeared to have greater anti-inflammatory and analgesic effects than DAS. Trial Registration Number 09073.
Isokinetic muscle strength and readiness to return to sport following anterior cruciate ligament reconstruction: is there an association? A systematic review and a protocol recommendation
Authors: Undheim Marit Baste , Cosgrave Ciaran , King Enda , Strike Siobhán , Marshall Brendan , Falvey Éanna , Franklyn-Miller Andrew 
Published: June 2015

IntroductionFollowing anterior cruciate ligament reconstruction (ACLR), strength is a key variable in regaining full function of the knee. Isokinetic strength is commonly used as part of the return to sport (RTS) criteria.AimWe systematically reviewed the isokinetic strength evaluation protocols that are currently being used following ACLR. A secondary aim was to suggest an isokinetic protocol that could meet RTS criteria.MethodArticles were searched using ScienceDirect, PubMed and Sage Journals Online, combined with cross-checked reference lists of the publications. Protocol data and outcome measurements and RTS criteria were extracted from each article included in the review.Results39 studies met the inclusion criteria and reported their isokinetic strength evaluation protocol following ACLR. The variables that were most commonly used were concentric/concentric mode of contraction (31 studies), angular velocity of 60°/s (29 studies), 3–5 repetitions (24 studies), range of motion of 0–90° (6 studies), and using gravity correction (9 studies). 8 studies reported strength limb symmetry index scores as part of their RTS criteria.ConclusionsThere was no standardised isokinetic protocol following ACLR; isokinetic strength measures have not been validated as useful predictors of successful RTS. We propose a standard protocol to allow consistency of testing and accurate comparison of future research.
Perceptions of medical students towards antibiotic prescribing for upper respiratory tract infections in Saudi Arabia
Authors: Harakeh Steve , Almatrafi Musab , Ungapen Haifa , Hammad Rotana , Olayan Feras , Hakim Reema , Ayoub Mohammed , Bakhsh Noura , Almasaudi Saad B , Barbour Elie , Bahijri Suhad , Azhar Esam , Damanhouri Ghazi , Qari Yousef , Kumosani Taha , Harakeh Zeena , Ahmad Muhammad S , Cals JochenW L 
Published: June 2015

IntroductionThis survey evaluates knowledge, attitudes and practices of medical students towards use of antibiotics for upper respiratory infections (URTIs).MethodologyCross-sectional questionnaire study among 1042 randomly selected medical students in Saudi Arabia.ResultsRespondents were mostly Saudis (97.5%), had previous knowledge of antibiotics (99.7%) and their usage (98.3%) against bacterial infections (93.7%). 18.1% thought that they could be used for viral infections. Nearly all students (97.2%) used antibiotics themselves during the previous year and self-medication without a prescription was high at 49% of cases. Most antibiotics were taken for URTI symptoms (61.8%). Female medical students had better knowledge on antibiotic effectiveness against bacteria and viruses, and overall knowledge increased with study year. Health seeking behaviour rates for symptoms of RTI and associated estimated necessity for antibiotics varied but were highest for cough with yellow/green phlegm.ConclusionsThe depth of knowledge that healthcare professionals have in relation to the proper use of antibiotics is essential in spreading the right message within communities. This is the first large study among medical students in Saudi Arabia, shedding important light on areas for improvement in the medical curriculum as well as antibiotic practices of medical students themselves.