bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Penicillium rubens platform strain for secondary metabolite production
Authors: Pohl Carsten , Polli Fabiola , Schütze Tabea , Viggiano Annarita , Mózsik László , Jung Sascha , de Vries Maaike , Bovenberg Roel A. L. , Meyer Vera , Driessen Arnold J. M. 
Published: May 2020

AbstractWe present a Penicillium rubens strain with an industrial background in which the four highly expressed biosynthetic gene clusters (BGC) required to produce penicillin, roquefortine, chrysogine and fungisporin were removed. This resulted in a minimal secondary metabolite background. Amino acid pools under steady-state growth conditions showed reduced levels of methionine and increased intracellular aromatic amino acids. Expression profiling of remaining BGC core genes and untargeted mass spectrometry did not identify products from uncharacterized BGCs. This platform strain was repurposed for expression of the recently identified polyketide calbistrin gene cluster and achieved high yields of decumbenone A, B and C. The penicillin BGC could be restored through in vivo assembly with eight DNA segments with short overlaps. Our study paves the way for fast combinatorial assembly and expression of biosynthetic pathways in a fungal strain with low endogenous secondary metabolite burden.
Revealing the complexity of ionic liquid–protein interactions through a multi-technique investigation
Authors: Bui-Le Liem , Clarke Coby J. , Bröhl Andreas , Brogan Alex P. S. , Arpino James A. J. , Polizzi Karen M. , Hallett Jason P. 
Published: May 2020

AbstractIonic liquids offer exciting possibilities for biocatalysis as solvent properties provide rare opportunities for customizable, energy-efficient bioprocessing. Unfortunately, proteins and enzymes are generally unstable in ionic liquids and several attempts have been made to explain why; however, a comprehensive understanding of the ionic liquid–protein interactions remains elusive. Here, we present an analytical framework (circular dichroism (CD), fluorescence, ultraviolet-visible (UV/Vis) and nuclear magnetic resonance (NMR) spectroscopies, and small-angle X-ray scattering (SAXS)) to probe the interactions, structure, and stability of a model protein (green fluorescent protein (GFP)) in a range (acetate, chloride, triflate) of pyrrolidinium and imidazolium salts. We demonstrate that measuring protein stability requires a similar holistic analytical framework, as opposed to single-technique assessments that provide misleading conclusions. We reveal information on site-specific ionic liquid–protein interactions, revealing that triflate (the least interacting anion) induces a contraction in the protein size that reduces the barrier to unfolding. Robust frameworks such as this are critical to advancing non-aqueous biocatalysis and avoiding pitfalls associated with single-technique investigations.
Genetic and expression variations of cell cycle pathway genes in brain tumor patients
Authors: Naqvi Anum Zehra , Mahjabeen Ishrat , Ameen Saima , Ahmed Malik Waqar , Khan Asad Ullah , Akram Zertashia , Kayani Mahmood Akhtar 
Published: May 2020

Abstract
The present study was designed to determine the association between the genetic polymorphisms/expression variations of RB1 and CCND1 genes and brain tumor risk. For this purpose, 250 blood samples of brain tumor patients along with 250 controls (cohort I) and 96 brain tumor tissues (cohort II) with adjacent control section were collected. Mutation analysis of RB1 (rs137853294, rs121913300) and CCND1 (rs614367, rs498136) genes was performed using ARMS-PCR followed by sequencing, and expression analysis was performed using real-time PCR and immunohistochemistry. The results showed homozygous mutant genotype of RB1 gene polymorphism, rs121913300 (P=0.003) and CCND1 gene polymorphism rs614367 (P=0.01) were associated significantly with brain tumor risk. Moreover, significant down-regulation of RB1 (P=0.005) and up-regulation of CCND1 (P=0.0001) gene was observed in brain tumor sections vs controls. Spearman correlation showed significant negative correlation between RB1 vs proliferation marker, Ki-67 (r = −0.291*, P&lt;0.05) in brain tumors. Expression levels of selected genes were also assessed at protein level using immunohistochemical analysis (IHC) and signification down-regulation of RB1 (P=0.0001) and up-regulation of CCND1 (P=0.0001) was observed in brain tumor compared with control sections. In conclusion, it is suggested that polymorphisms/expression variations of RB1 and CCND1 genes may be associated with increased risk of brain tumor.
High-speed stars: Galactic hitchhikers
Authors: Caffau E. , Monaco L. , Bonifacio P. , Sbordone L. , Haywood M. , Spite M. , Di Matteo P. , Spite F. , Mucciarelli A. , François P. , Matas Pinto A. M. 
Published: May 2020

Context.The search for stars born in the very early stages of the Milky Way star formation history is of paramount importance in the study of the early Universe since their chemistry carries irreplaceable information on the conditions in which early star formation and galaxy buildup took place. The search for these objects has generally taken the form of expensive surveys for faint extremely metal-poor stars, the most obvious but not the only candidates to a very early formation.Aims.Thanks toGaiaDR2 radial velocities and proper motions, we identified 72 bright cool stars displaying heliocentric transverse velocities in excess of 500 km s−1. These objects are most likely members of extreme outer-halo populations, either formed in the early Milky Way build-up or accreted from since-destroyed self-gravitating stellar systems.Methods.We analysed low-resolution FORS spectra of the 72 stars in the sample and derived the abundances of a few elements. Despite the large uncertainties on the radial velocity determination, we derived reliable orbital parameters for these objects.Results.The stars analysed are mainly slightly metal poor, with a few very metal-poor stars. Their chemical composition is much more homogeneous than expected. All the stars have very eccentric halo orbits, some extending well beyond the expected dimension of the Milky Way.Conclusions.These stars can be the result of a disrupted small galaxy or they could have been globular cluster members. Age estimates suggest that some of them are evolved blue stragglers, now on the subgiant or asymptotic giant branches.
Interaction morphology and bond strength of nanofilled simplified-step adhesives to acid etched dentin
Authors: Hipólito Vinicius Di , Reis André Figueiredo , Mitra Sumita B , de Goes Mario Fernando 
Published: May 2020

ABSTRACTObjective: To evaluate the effect of nanofillers incorporated into adhesives on the microtensile bond strength (μ-TBS) and interfacial micromorphology to dentin.Methods: The occlusal enamel of 5 human molars was removed and each tooth sectioned into four quarters. The exposed dentin was treated with one of the following adhesives: Adper Single Bond (SB-unfilled), OptiBond Solo Plus (OS-barium aluminoborosilicate, 400nm Ø), Prime & Bond NT (NT-colloidal silica, 7-40 nm Ø) and Adper Single Bond 2 (SB2-colloidal silica, 5nm Ø). Cylinders of resin-based composite were constructed on the adhesive layers. After 24-hour storage, the restored tooth-quadrants were sectioned to obtain stick-shaped specimens (0.8 mm2, cross-sectional area) and submitted to μ-TBS at a cross-speed of 0.5 mm/min. Data were analyzed using one-way ANOVA and Tukey’s test (alpha = .05). Twenty-eight additional teeth were used for interfacial micromorphologic analysis by SEM (16-teeth) and TEM (12-teeth). The dentin surfaces of 32 discs were treated with the adhesives (8 discs for adhesive) and laminated to form disc-pairs using a flowable resin composite for SEM/EDS analysis. For TEM, 90nm-thick nondemineralized unstained sections were processed.Results: SB2 showed significant higher bond strength than SB, OS and NT. The SEM/EDS and TEM analysis revealed nanofillers infiltrated within the interfibrillar spaces of the SB2-hybrid layer. Fillers were concentrated around patent tubular orifices and in the adhesive layer for OS and NT.Conclusion: The presence of nanofillers within the interfibrillar spaces of the SB2-hybrid layer suggests its importance in the improvement of the μ-TBS. (Eur J Dent 2012;6:349-360)
Parental knowledge and attitudes regarding the emergency treatment of avulsed permanent teeth
Authors: Ozer Sezin , Yilmaz Elif Ipek , Bayrak Sule , Tunc Emine Sen 
Published: May 2020

ABSTRACTObjective: The aim of this study was to examine parental knowledge and attitudes about avulsed permanent teeth and their emergency treatment in children.Methods: A total of 289 parents of children aged 6-12 years receiving care at the Ondokuz Mayis University Pediatric Dentistry Clinic were included in the study. Questionnaires were used to collect data on parents’ demographic characteristics, previous training in traumatic dental injury and treatment and knowledge of avulsed permanent teeth and their emergency management. Chi-square tests were used to identify differences in responses for different variables.Results: More than half of the participating parents were female (69.6%) and between the age of 30-39 years (64.4%). Most (90.7%) reported that they would not replant the avulsed tooth in its socket, and most (68.2%) gave correct answers regarding the optimum time for which an avulsed tooth should be left out of the mouth prior to replantation. However, most parents were not sufficiently informed about the appropriate method for cleaning a dirty avulsed tooth or transporting it to a dentist or doctor. None of the demographic characteristics or training status was found to have a statistically significant effect on the number of correct responses regarding appropriate management of avulsion injuries (P>.05)Conclusion: This study revealed that the parental level of knowledge about the emergency treatment of avulsion in children is inadequate and that educational campaigns are necessary to improve proper emergency management of dental avulsion. (Eur J Dent 2012;6:370-375)
Apical third enlargement of the root canal and its relationship with the repair of periapical lesions
Authors: Souza Ronaldo Araújo , Dantas João Costa Pinto , Brandão Paula Maciel , Colombo Suely , Lago Maurício , Duarte Marco Antônio Húngaro 
Published: May 2020

ABSTRACTObjective: The purpose of this study was to evaluate if the apical third enlargement of root canal is the determinant factor for the repair of periapical lesions in endodontic treatment.Methods: Eighty upper and lower incisors, canines and premolars with periapical lesions were randomly divided in 2 groups and were treated by undergraduate students. Canals were instrumented with up to 3 files in group I (n = 40) and up to 4 files in group II (n = 40) 1 mm short of the apex and were filled with a calcium hydroxide dressing. After removing calcium hydroxide 14 days later, both groups were filled using the lateral condensation technique. In the 2-year follow-up, a few patients did not return, and some cases did not present conditions for accurate comparisons. Therefore, only 43 patients (24 in group I and 19 in group II) presented conditions for radiographic comparisons. Data were statistically analyzed using Fisher's exact test.Results: Comparison of the initial and follow-up radiographs showed that 22 out of 24 (91.67%) patients in group I and 17 out of 19 patients (89.47%) in group II showed repair. Statistical analysis revealed no significant differences between the groups (P>.05).Conclusion: The results of this study show that the apical third enlargement did not alter the outcome of endodontic treatment of teeth with periapical lesion performed by undergraduate students. (Eur J Dent 2012;6:385-388)
Can extended photoactivation time of resin-based fissure sealer materials improve ultimate tensile strength and decrease water sorption/solubility?
Authors: Borges Boniek Castillo Dutra , Souza-Júnior Eduardo José , Catelan Anderson , Sartini Paulillo Luís Alexandre Maffei , Aguiar Flávio Henrique Baggio 
Published: May 2020

ABSTRACTObjective: This study aimed to evaluate the impact of extended photoactivation time on ultimate tensile strength (UTS), water sorption (WS) and solubility (WSB) of resin-based materials used as fissure-sealantsMethods: A fissure-sealant (Fluroshield) and a flowable composite (Permaflo) polymerized for 20 and 60 seconds were tested. For UTS, 20 hourglass shaped samples were prepared representing two materials and two photoactivation time (n=5). After 24-h dry-storage, samples were tested in tension using a universal testing machine at a cross-head speed of 0.5 mm/min (UTS was calculated in MPa). For WS and WSB, 20 disks with 5 mm diameter and 1 mm height (n=5) were prepared and volumes were calculated (mm3). They were transferred to desiccators until a constant mass was obtained (m1) and were subsequently immersed in distilled water until no alteration in mass was detected (m2). Samples were reconditioned to constant mass in desiccators (m3). WS and WSB were determined using the equations m2-m3/V and m1-m3/V, respectively. Data were subjected to twoway ANOVA and Tukey’s HSD test (P<.05).Results: There was no significant difference between materials or photoactivation times for the UTS and WS. Permaflo presented lower but negative WSB compared to Fluroshield.Conclusions: Extended photoactivation time did not improve the physical properties tested. Fluroshield presented physical properties that were similar to or better than Permaflo. (Eur J Dent 2012;6:402-407)
In vitro antibacterial effects of glassionomer cement containing ethanolic extract of propolis on Streptococcus mutans
Authors: Topcuoglu Nursen , Ozan Fatih , Ozyurt Mustafa , Kulekci Guven 
Published: May 2020

ABSTRACTObjective: The aim of this study was to evaluate the antibacterial property of glass-ionomer cement (GIC) containing propolis against Streptococcus mutans and its effect on the in vitro S. mutans biofilm formation.Methods: Ethanolic extract of propolis (EEP) was prepared at two concentrations as 25 and 50%. Three different experimental GIC disks were prepared using pure liquid and liquid solutions diluted with 25 and 50 percent of EEP concentrations. Minimum inhibitory concentration (MIC) of EEP on the growth of S. mutans ATCC 25175 was determined by using agar dilution method. Agar diffusion test and an in vitro S. mutans biofilm assay for GIC disks with and without EEP were performedResults: MIC values of Turkish propolis for S. mutans ATCC 25175 was found as 25 μg/mL. Experimental GICs containing propolis exhibited inhibition zones and their dry biofilm weights were less than the pure GIC. The bacterial density was lower in the GIC containing 50% EEP.Conclusions: A distinct antibacterial and antibiofilm efficacy of propolis containing GIC on S. mutans has been observed. Although further research is needed to show clinical results, antibacterial GIC containing propolis would be a promising material for restoration. (Eur J Dent 2012;6:428-433)
Infected Pancreatic Hydatid Cyst with Cysto-Pancreatic Fistula Presenting as Acute Pancreatitis
Authors: Daniel Phillip , Shukla Siddharth , Prabhakar Nidhi , Kulkarni Aditya , Sharma Ravi , Gupta Rajesh , Rana Surinder Singh 
Published: May 2020

AbstractHydatid cysts can be found in almost any organ of the body with the most common sites being liver, lung, spleen, and kidney. A pancreatic hydatid cyst is rare but an isolated pancreatic hydatid cyst is even rarer. Cysts in the head of pancreas usually present with jaundice, whereas cysts located in the body and tail are usually asymptomatic. We present a rare case of isolated pancreatic hydatid cyst that presented with acute pancreatitis and mimicked a pancreatic fluid collection.
Combination of Oral Anticoagulants and Single Antiplatelets versus Triple Therapy in Nonvalvular Atrial Fibrillation and Acute Coronary Syndrome: Stroke Prevention among Asians
Authors: Santoso Anwar , Raharjo Sunu B. 
Published: May 2020

AbstractAtrial fibrillation (AF), the most prevalent arrhythmic disease, tends to foster thrombus formation due to hemodynamic disturbances, leading to severe disabling and even fatal thromboembolic diseases. Meanwhile, patients with AF may also present with acute coronary syndrome (ACS) and coronary artery disease (CAD) requiring stenting, which creates a clinical dilemma considering that majority of such patients will likely receive oral anticoagulants (OACs) for stroke prevention and require additional double antiplatelet treatment (DAPT) to reduce recurrent cardiac events and in-stent thrombosis. In such cases, the gentle balance between bleeding risk and atherothromboembolic events needs to be carefully considered. Studies have shown that congestive heart failure, hypertension, age ≥ 75 years (doubled), diabetes mellitus, and previous stroke or transient ischemic attack (TIA; doubled)–vascular disease, age 65 to 74 years, sex category (female; CHA2DS2-VASc) scores outperform other scoring systems in Asian populations and that the hypertension, abnormal renal/liver function (1 point each), stroke, bleeding history or predisposition, labile international normalized ratio (INR), elderly (>65 years), drugs/alcohol concomitantly (1 point each; HAS-BLED) score, a simple clinical score that predicts bleeding risk in patients with AF, particularly among Asians, performs better than other bleeding scores. A high HAS-BLED score should not be used to rule out OAC treatment but should instead prompt clinicians to address correctable risk factors. Therefore, the current review attempted to analyze available data from patients with nonvalvular AF who underwent stenting for ACS or CAD and elaborate on the direct-acting oral anticoagulant (DOAC) and antiplatelet management among such patients. For majority of the patients, “triple therapy” comprising OAC, aspirin, and clopidogrel should be considered for 1 to 6 months following ACS. However, the optimal duration for “triple therapy” would depend on the patient's ischemic and bleeding risks, with DOACs being obviously safer than vitamin-K antagonists.
Prosthetic Reconstruction of the Maxilla and Palate
Authors: Pool Christopher , Shokri Tom , Vincent Aurora , Wang Weitao , Kadakia Sameep , Ducic Yadranko 
Published: May 2020

AbstractMaxillary defects commonly present following surgical resection of oncologic processes. The use of rotational and free flaps has largely replaced the use of prosthetic options for hard palate and maxillary reconstruction, but prostheses remain a useful tool. Prosthetic devices may be invaluable in patients considered poor candidates for surgical reconstruction secondary to poor vascularity, need for postoperative radiation, or medical comorbidities that place them at high risk for healing following reconstruction. Obturators may also be considered over soft tissue options if oncologic surveillance via direct visualization of the surgical site is warranted.
Visiting Student Away Rotations in Ophthalmology: A Study of Medical Students' Experiences and Perspectives
Authors: Patel Sunny B. , Kelly Lisa D. 
Published: May 2020

Abstract
Background Despite the frequency of medical students' participation in ophthalmology clerkships away from their home institution, the impact and benefit of these clerkships have remained uninvestigated. To date, no study has focused specifically on medical student perspectives of away ophthalmology clerkships.
Objective The purpose of the study was to evaluate the medical students' perspectives on and experience with away rotations in ophthalmology, and assess their effect on residency Match outcomes.
Methods An anonymous, original, online survey was designed and distributed to applicants of the 2015 to 2018 ophthalmology Match cycles.
Results A total of 69 responses from nine medical institutions were collected (62% response rate). Forty-one respondents (59%) chose to perform at least one away rotation. Among away rotators, the mean number performed was 1.44. Thirty-seven away rotators (90%) reported receiving an interview from at least one host institution they visited. The average estimated cost of an away rotation was ∼1,709 U.S. dollars. With a 95.7% overall match rate among the respondents, no statistically significant difference was seen in match rates between away rotators and nonaway rotators (p = 0.564). Among the away rotators, the mean position on their rank order list matched was 2.34, while the nonaway rotators matched at a mean position of 2.13 (p = 0.383).
Conclusion No association between away participation and success in the San Francisco Match was observed in this study. However, study participants did experience non-Match-related benefits from away elective participation.
Reconstruction of the Midface and Palate
Authors: Bender-Heine Adam , Wax Mark K. 
Published: May 2020

AbstractThe midface is a complex anatomic structure that is fundamental to many physiologic and homeostatic functions. It may be involved in many pathologic processes that require partial or complete removal. When this happens, reconstruction is mandatory to improve cosmetic outcome with its effect on social interaction as well as to provide an opportunity for complete orodental rehabilitation with restoration of all physiologic functions. This article will review the different reconstructive options available for complex defects of the maxillofacial complex. It will highlight the surgical options available to maximize functional restoration. Finally, it will discuss computer modeling to optimize reconstructive planning.
Role of Factor XIa and Plasma Kallikrein in Arterial and Venous Thrombosis
Authors: Visser Mayken , Heitmeier Stefan , ten Cate Hugo , Spronk Henri M. H. 
Published: May 2020

AbstractCardiovascular disease, including stroke, myocardial infarction, and venous thromboembolism, is one of the leading causes of morbidity and mortality worldwide. Excessive coagulation may cause vascular occlusion in arteries and veins eventually leading to thrombotic diseases. Studies in recent years suggest that coagulation factors are involved in these pathological mechanisms. Factors XIa (FXIa), XIIa (FXIIa), and plasma kallikrein (PKa) of the contact system of coagulation appear to contribute to thrombosis while playing a limited role in hemostasis. Contact activation is initiated upon autoactivation of FXII on negatively charged surfaces. FXIIa activates plasma prekallikrein (PK) to PKa, which in turn activates FXII and initiates the kallikrein–kinin pathway. FXI is also activated by FXIIa, leading to activation of FIX and finally to thrombin formation, which in turn activates FXI in an amplification loop. Animal studies have shown that arterial and venous thrombosis can be reduced by the inhibition of FXI(a) or PKa. Furthermore, data from human studies suggest that these enzymes may be valuable targets to reduce thrombosis risk. In this review, we discuss the structure and function of FXI(a) and PK(a), their involvement in the development of venous and arterial thrombosis in animal models and human studies, and current therapeutic strategies.
Cell entry mechanisms of SARS-CoV-2
Authors: Shang Jian , Wan Yushun , Luo Chuming , Ye Gang , Geng Qibin , Auerbach Ashley , Li Fang 
Published: May 2020

Significance
A key to curbing SARS-CoV-2 is to understand how it enters cells. SARS-CoV-2 and SARS-CoV both use human ACE2 as entry receptor and human proteases as entry activators. Using biochemical and pseudovirus entry assays and SARS-CoV as a comparison, we have identified key cell entry mechanisms of SARS-CoV-2 that potentially contribute to the immune evasion, cell infectivity, and wide spread of the virus. This study also clarifies conflicting reports from recent studies on cell entry of SARS-CoV-2. Finally, by highlighting the potency and the evasiveness of SARS-CoV-2, the study provides insight into intervention strategies that target its cell entry mechanisms.