bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of welding speed on microstructure, hardness and tensile properties in laser welding of advanced high strength steel
Authors: Zhao Y Y , Zhang Y S , Hu W
Published: September 2013

The increasing demand of lightweight and durability makes advanced high strength steel attractive for future automotive applications. In this study, 0·8 mm thick bare 600, 800 and 1000 MPa grade dual phase steel and 1500 MPa grade martensitic steel were laser welded, and the effect of welding speed on weld bead geometry, microhardness, microstructure and tensile properties was investigated. The steels exhibited similar weldability, and a critical welding speed for acceptable joint was determined as 25 mm s−1. A linear relationship of the hardness at fusion zone with carbon equivalent was observed, while carbon content showed a poorer linear fit. Heat affected zone (HAZ) softening increased with the steel grades due to the higher martensite volume fraction of the base metal in stronger steels. In addition, decrease of welding speed led to longer tempering time and consequently higher degree of HAZ softening. Correlations between tensile strength and hardness were also investigated.
Evaluation of residual plastic strain distribution in dissimilar metal weld by hardness mapping
Authors: Qiao D , Zhang W , Pan T-Y , Crooker P , David S , Feng Z
Published: September 2013

The knowledge of residual plastic strains is a prerequisite for studying the stress corrosion cracking in dissimilar metal welds common to nuclear power plant structures. In this work, the distribution of residual equivalent plastic strains in a multipass dissimilar metal weld composed of nickel alloy 82 and austenitic stainless steel 304L is evaluated quantitatively through microhardness mapping. The contribution to hardness from the plastic strain (workhardening) is separated from that from the chemistry variation in the dissimilar metal weld. It is found that high equivalent plastic strains are predominately accumulated in the buttering layer, the root pass and the heat affected zone, which experience multiple welding thermal cycles. The final cap passes, experiencing only one or two welding thermal cycles, exhibit less plastic strain accumulation. Moreover, the experimental residual plastic strains are compared with those predicted using an existing weld thermomechanical model with two different strain hardening rules. The importance of considering the dynamic strain hardening recovery due to high temperature exposure in welding is discussed for the accurate simulation of weld residual stresses and plastic strains. Finally, the experimental result reveals that the typical post-buttering heat treatment for residual stress relief may not completely eliminate the residual plastic strains in the buttering layer.
Comparison of single and double pass friction stir welding of skin–stringer aviation aluminium alloy
Authors: He D , Yang K , Li M , Guo H , Li N , Lai R , Ye S
Published: September 2013

To enhance the strength of the skin–stringer structures used in aircraft, comparative tests between single and double pass friction stir welding (FSW) were performed. Aluminium alloy was used for the skin (2524-T3, 1·8 mm) and stringer (7150-T77511, 2·4 mm). An equilateral right angled structure was used, and perfect joints without internal defects were obtained. Tensile, peel and metallographic tests were also implemented. The results show that the average peel strength of a double pass FSW joint is at least twice that from single pass FSW. Therefore, double pass FSW is an effective way of improving the connection strength of an aircraft skin–stringer structure.
Acquired copy number alterations of miRNA genes in acute myeloid leukemia are uncommon
Authors: Ramsingh Giridharan , Jacoby Meagan A. , Shao Jin , De Jesus Pizzaro Rigoberto E. , Shen Dong , Trissal Maria , Getz Angela H. , Ley Timothy J. , Walter Matthew J. , Link Daniel C.
Published: September 2013

Key Points

Somatic copy number alterations of miRNA genes are uncommon in de novo and secondary AML. MIR223 silencing in AML occurs through both genetic and epigenetic mechanisms.
Defining characteristics of classical Hodgkin lymphoma microenvironment T-helper cells
Authors: Greaves Paul , Clear Andrew , Owen Andrew , Iqbal Sameena , Lee Abigail , Matthews Janet , Wilson Andrew , Calaminici Maria , Gribben John G.
Published: September 2013

Key Points

Hodgkin lymphoma microenvironment T-helper cells express TH1/activation markers and lack TH2/immunosuppression markers. These cells are functional, retaining the capacity for cytokine secretion and proliferation in vitro.
Hematopoietic cell transplantation and HIV cure: where we are and what next?
Authors: Zou Shimian , Glynn Simone , Kuritzkes Daniel , Shah Monica , Cook Nakela , Berliner Nancy
Published: September 2013

The report of the so-called Berlin patient cured of HIV with hematopoietic stem cell transplantation and a few other studies raised tremendous hope, excitement, and curiosity in the field. The National Heart, Lung and Blood Institute of the National Institutes of Health convened a Working Group to address emerging heart, lung, and blood research priorities related to HIV infection. Hematopoietic cells could contribute to HIV cure through allogeneic or autologous transplantation of naturally occurring or engineered cells with anti-HIV moieties. Protection of central memory T cells from HIV infection could be a critical determinant of achieving a functional cure. HIV cure can only be achieved if the virus is eradicated from reservoirs in resting T cells and possibly other hematopoietic cells. The Working Group recommended multidisciplinary efforts leveraging HIV and cell therapy expertise to answer the critical need to support research toward an HIV cure.
Transplacental transmission of field and rescued strains of BTV-2 and BTV-8 in experimentally infected sheep
Authors: Rasmussen Lasse Dam , Savini Giovanni , Lorusso Alessio , Bellacicco Anna , Palmarini Massimo , Caporale Marco , Rasmussen Thomas Bruun , Belsham Graham J , Bøtner Anette
Published: September 2013

Transplacental transmission of bluetongue virus has been shown previously for the North European strain of serotype 8 (BTV-8) and for tissue culture or chicken egg-adapted vaccine strains but not for field strains of other serotypes. In this study, pregnant ewes (6 per group) were inoculated with either field or rescued strains of BTV-2 and BTV-8 in order to determine the ability of these viruses to cross the placental barrier. The field BTV-2 and BTV-8 strains was passaged once in Culicoides KC cells and once in mammalian cells. All virus inoculated sheep became infected and seroconverted against the different BTV strains used in this study. BTV RNA was detectable in the blood of all but two ewes for over 28 days but infectious virus could only be detected in the blood for a much shorter period. Interestingly, transplacental transmission of BTV-2 (both field and rescued strains) was demonstrated at high efficiency (6 out of 13 lambs born to BTV-2 infected ewes) while only 1 lamb of 12 born to BTV-8 infected ewes showed evidence of in utero infection. In addition, evidence for horizontal transmission of BTV-2 between ewes was observed. As expected, the parental BTV-2 and BTV-8 viruses and the viruses rescued by reverse genetics showed very similar properties to each other. This study showed, for the first time, that transplacental transmission of BTV-2, which had been minimally passaged in cell culture, can occur; hence such transmission might be more frequent than previously thought.
Multiple introductions of serotype O foot-and-mouth disease viruses into East Asia in 2010–2011
Authors: Valdazo-González Begoña , Timina Anna , Scherbakov Alexey , Abdul-Hamid Nor Faizah , Knowles Nick J , King Donald P
Published: September 2013

Foot-and-mouth disease virus (FMDV) is a highly contagious and genetically variable virus. Sporadic introductions of this virus into FMD-free countries may cause outbreaks with devastating consequences. In 2010 and 2011, incursions of the FMDV O/SEA/Mya-98 strain, normally restricted to countries in mainland Southeast Asia, caused extensive outbreaks across East Asia. In this study, 12 full genome FMDV sequences for representative samples collected from the People’s Republic of China (PR China) including the Hong Kong Special Administrative Region (SAR), the Republic of Korea, the Democratic People’s Republic of Korea, Japan, Mongolia and The Russian Federation were generated and compared with additional contemporary sequences from viruses within this lineage. These complete genomes were 8119 to 8193 nucleotides in length and differed at 1181 sites, sharing a nucleotide identity ≥ 91.0% and an amino acid identity ≥ 96.6%. An unexpected deletion of 70 nucleotides within the 5′-untranslated region which resulted in a shorter predicted RNA stem-loop for the S-fragment was revealed in two sequences from PR China and Hong Kong SAR and five additional related samples from the region. Statistical parsimony and Bayesian phylogenetic analysis provide evidence that these outbreaks in East Asia were generated by two independent introductions of the O/SEA/Mya-98 lineage sometime between August 2008 and March 2010. The rapid emergence of these viruses from Southeast Asia highlights the importance of adopting approaches to closely monitor the spread of this lineage that now poses a threat to livestock industries in other regions.
The interRAI Acute Care instrument incorporated in an eHealth system for standardized and web-based geriatric assessment: strengths, weaknesses, opportunities and threats in the acute hospital setting
Authors: Devriendt Els , Wellens Nathalie I H , Flamaing Johan , Declercq Anja , Moons Philip , Boonen Steven , Milisen Koen
Published: September 2013

Background

The interRAI Acute Care instrument is a multidimensional geriatric assessment system intended to determine a hospitalized older persons’ medical, psychosocial and functional capacity and needs. Its objective is to develop an overall plan for treatment and long-term follow-up based on a common set of standardized items that can be used in various care settings. A Belgian web-based software system (BelRAI-software) was developed to enable clinicians to interpret the output and to communicate the patients’ data across wards and care organizations. The purpose of the study is to evaluate the (dis)advantages of the implementation of the interRAI Acute Care instrument as a comprehensive geriatric assessment instrument in an acute hospital context.

Methods

In a cross-sectional multicenter study on four geriatric wards in three acute hospitals, trained clinical staff (nurses, occupational therapists, social workers, and geriatricians) assessed 410 inpatients in routine clinical practice. The BelRAI-system was evaluated by focus groups, observations, and questionnaires. The Strengths, Weaknesses, Opportunities and Threats were mapped (SWOT-analysis) and validated by the participants.

Results

The primary strengths of the BelRAI-system were a structured overview of the patients’ condition early after admission and the promotion of multidisciplinary assessment. Our study was a first attempt to transfer standardized data between home care organizations, nursing homes and hospitals and a way to centralize medical, allied health professionals and nursing data. With the BelRAI-software, privacy of data is guaranteed. Weaknesses are the time-consuming character of the process and the overlap with other assessment instruments or (electronic) registration forms. There is room for improving the user-friendliness and the efficiency of the software, which needs hospital-specific adaptations. Opportunities are a timely and systematic problem detection and continuity of care. An actual shortage of funding of personnel to coordinate the assessment process is the most important threat.

Conclusion

The BelRAI-software allows standardized transmural information transfer and the centralization of medical, allied health professionals and nursing data. It is strictly secured and follows strict privacy regulations, allowing hospitals to optimize (transmural) communication and interaction. However, weaknesses and threats exist and must be tackled in order to promote large scale implementation.
Antenatal education and the birthing experience of Brazilian women: a qualitative study
Authors: Miquelutti Maria Amelia , Cecatti José Guilherme , Makuch Maria Yolanda
Published: September 2013

Background

Information is still scarce on the birthing experience of women who participate in antenatal systematic education programs. The objective of the study was to report the experience of labor as described by nulliparous women who participated and who did not in a systematic Birth Preparation Program (BPP).

Method

A qualitative study was conducted with eleven women who participated in a BPP and ten women attending routine prenatal care selected through purposeful sampling. The BPP consisted of systematized antenatal group meetings structured to provide physical exercise and information on pain prevention during pregnancy, the role of the pelvic floor muscles, the physiology of labor, and pain relief techniques. A single, semi-structured interview was conducted with each participant. All interviews were recorded, transcribed verbatim and thematic analyses performed. The relevant themes were organized in the following categories of analysis: control of labor, positions adopted during labor, and satisfaction with labor.

Results

Women who participated in the systematic educational activities of the BPP reported they maintained self-control during labor and used breathing exercises, exercises on the ball, massage, baths and vertical positions to control pain. Also they reported satisfaction with their birthing experience. Women who did not participate in systematic educational activities referred to difficulties in maintaining control during labor and almost half of them reported lack of control. Also they were more likely to report dissatisfaction with labor.

Conclusions

Women who participated in the BPP reported self-control during labor and used non-pharmacological techniques to control pain and facilitate labor and expressed satisfaction with the birthing experience.
Labisia pumila regulates bone-related genes expressions in postmenopausal osteoporosis model
Authors: Fathilah Siti Noor , Mohamed Norazlina , Muhammad Norliza , Mohamed Isa Naina , Soelaiman Ima Nirwana , Shuid Ahmad Nazrun
Published: September 2013

Background

Labisia Pumila var. alata (LPva) has shown potential as an alternative to estrogen replacement therapy (ERT) in prevention of estrogen-deficient osteoporosis. In earlier studies using postmenopausal model, LPva was able to reverse the ovariectomy-induced changes in biochemical markers, bone calcium, bone histomorphometric parameters and biomechanical strength. The mechanism behind these protective effects is unclear but LPva may have regulated factors that regulate bone remodeling. The aim of this study is to determine the bone-protective mechanism of LPva by measuring the expressions of several factors involved in bone formative and resorptive activities namely Osteoprotegerin (OPG), Receptor Activator of Nuclear Factor kappa-B Ligand (RANKL), Macrophage-Colony Stimulating Factor (MCSF) and Bone Morphogenetic Protein-2 (BMP-2).

Methods

Thirty-two female Wistar rats were randomly divided into four groups: Sham-operated (Sham), ovariectomized control (OVXC), ovariectomized with Labisia pumila var. alata (LPva) and ovariectomized with ERT (Premarin®) (ERT). The LPva and ERT were administered via daily oral gavages at doses of 17.5 mg/kg and 64.5 μg/kg, respectively. Following two months of treatment, the rats were euthanized and the gene expressions of BMP-2, OPG, RANKL and MCSF in the femoral bones were measured using a branch - DNA technique.

Results

The RANKL gene expression was increased while the OPG and BMP-2 gene expressions were reduced in the OVXC group compared to the SHAM group. There were no significant changes in the MCSF gene expressions among the groups. Treatment with either LPva or ERT was able to prevent these ovariectomy-induced changes in the gene expressions in ovariectomized rats with similar efficacy.

Conclusion

LPva may protect bone against estrogen deficiency-induced changes by regulating the RANKL, OPG and BMP-2 gene expressions.
The standardized herbal formula, PM014, ameliorated cigarette smoke-induced lung inflammation in a murine model of chronic obstructive pulmonary disease
Authors: Jung Kyung-Hwa , Haam Kyoung-Keun , Park Soojin , Kim Youngeun , Lee Seung Ryel , Lee Geunhyeog , Kim Miran , Hong Moochang , Shin Minkyu , Jung Sungki , Bae Hyunsu
Published: September 2013

Background

In this study, we evaluated the anti-inflammatory effect of PM014 on cigarette smoke induced lung disease in the murine animal model of chronic obstructive pulmonary disease (COPD).

Methods

Mice were exposed to cigarette smoke (CS) for 2 weeks to induce COPD-like lung inflammation. Two hours prior to cigarette smoke exposure, the treatment group was administered PM014 via an oral injection. To investigate the effects of PM014, we assessed PM014 functions in vivo, including immune cell infiltration, cytokine profiles in bronchoalveolar lavage (BAL) fluid and histopathological changes in the lung. The efficacy of PM014 was compared with that of the recently developed anti-COPD drug, roflumilast.

Results

PM014 substantially inhibited immune cell infiltration (neutrophils, macrophages, and lymphocytes) into the airway. In addition, IL-6, TNF-α and MCP-1 were decreased in the BAL fluid of PM014-treated mice compared to cigarette smoke stimulated mice. These changes were more prominent than roflumilast treated mice. The expression of PAS-positive cells in the bronchial layer was also significantly reduced in both PM014 and roflumilast treated mice.

Conclusions

These data suggest that PM014 exerts strong therapeutic effects against CS induced, COPD-like lung inflammation. Therefore, this herbal medicine may represent a novel therapeutic agent for lung inflammation in general, as well as a specific agent for COPD treatment.
The complexity of bladder cancer: long noncoding RNAs are on the stage
Authors: Zhang Quanan , Su Mo , Lu Guangming , Wang Jiangdong
Published: September 2013

The mammalian genome encodes thousands of long noncoding RNAs (lncRNAs) and it is increasingly clear that lncRNAs are key regulators of cellular function and development. Gain and/or loss of function studies in cell culture indicate that lncRNAs can regulate gene transcription indirectly through the targeting and recruitment of chromatin-modifying complexes as well as directly at the transcriptional or posttranscriptional levels. LncRNA biology is attracting great attention in cancer research because dysregulated lncRNAs occur in a variety of cancers, placing lncRNAs on the stage of cancer genome research. We briefly describe the latest lncRNA biology and discuss the oncogenic lncRNAs involved in core pathways in bladder cancer and the application of lncRNAs to its diagnosis and targeted treatment. LncRNAs are becoming essential components of the gene regulatory circuitry in the complexity of bladder cancer.
Caudate lobe resections: a single-center experience and evaluation of factors predictive of outcomes
Authors: Philips Prejesh , Farmer Russell W , Scoggins Charles R , McMasters Kelly M , Martin Robert CG
Published: September 2013

Background

Despite the increasing frequency of liver resection for multiple types of disease, caudate lobe resection remains a rare surgical event. The goal of this study is to review our experience and evaluate possible predictors of adverse outcomes in patients undergoing caudate lobectomy.

Methods

We reviewed a 1,900-patient prospective hepato-pancreatico-biliary database from January 2000 to December 2011, identifying 36 hepatectomy patients undergoing caudate lobe resection. Clinicopathologic characteristic and outcome data were compared using chi-square, T-test, ANOVA, Kaplan-Meier, and Cox regression analysis. Primary endpoints were the incidence and severity of complications, and secondary endpoints were blood loss, hospital stay, and transfusion requirements. Patients were also divided in two groups with group A being patients operated on before December 2007 and group B after 2007. We compared the demographics, risk factors, complication rates, and operative details between the two groups.

Results

Thirty-six patients underwent caudate lobe resection for cholangiocarcinoma (47.2%), metastatic colorectal cancer (36.1%), hepatocellular carcinoma (8.3%), or benign disease (8.3%). Nine patients (29%) had additional liver resection. Median overall survival (OS) was 21 months. Complications occurred in 52.7% (19/36) of patients with a median grade of 2. Tobacco abuse was associated with an increased risk of operative complications (73.3% vs. 38.9%, p = 0.03). Prior history of cardiac disease was associated with a higher complication rate (87% vs. 42%, p = 0.03). Neoadjuvant chemotherapy, biliary procedures, hepatitis, and prior major abdominal surgery were not predictive of complications. Major complication was also predicted by the volume of RBC transfusion (2.7 vs. 4.1 units, p = 0.003). In our subgroup analysis of the patients undergoing surgery before and after 2007, the two groups were well matched based on age, comorbidities, and risk factors. The complication rates and rates of high-grade complications were similar, but blood loss (600 ml vs. 400 ml, p = 0.03), inflow occlusion time (Pringle time 12.6 vs. 6, p = 0.00), and hospital stay (9.5 vs. 7 days, p = 0.01) were significantly lower in group B.

Conclusions

With appropriate patient selection, caudate lobe resection is an effective component of surgery for hepatic disease. Tobacco use and prior cardiac history increase the risk of complications.
Involvement of neuronal IL-1β in acquired brain lesions in a rat model of neonatal encephalopathy
Authors: Savard Alexandre , Lavoie Karine , Brochu Marie-Elsa , Grbic Djordje , Lepage Martin , Gris Denis , Sebire Guillaume
Published: September 2013

Background

Infection-inflammation combined with hypoxia-ischemia (HI) is the most prevalent pathological scenario involved in perinatal brain damage leading to life-long neurological disabilities. Following lipopolysaccharide (LPS) and/or HI aggression, different patterns of inflammatory responses have been uncovered according to the brain differentiation stage [Brochu et al.: J Neuroinflammation 8:55, 2011]. In fact, LPS pre-exposure has been reported to aggravate HI brain lesions in post-natal day 1 (P1) and P7 rat models that are respectively equivalent - in terms of brain development - to early and late human preterm newborns. However, little is known about the innate immune response in LPS plus HI-induced lesions of the full-term newborn forebrain and the associated neuropathological and neurobehavioral outcomes.

Methods

An original preclinical rat model has been previously documented for the innate neuroimmune response at different post-natal ages [Brochu et al.: J Neuroinflammation 8:55, 2011]. It was used in the present study to investigate the neuroinflammatory mechanisms that underline neurological impairments after pathogen-induced inflammation and HI in term newborns.

Results

LPS and HI exerted a synergistic detrimental effect on rat brain. Their effect led to a peculiar pattern of parasagittal cortical-subcortical infarcts mimicking those in the human full-term newborn with subsequent severe neurodevelopmental impairments. An increased IL-1β response in neocortical and basal gray neurons was demonstrated at 4 h after LPS + HI-exposure and preceded other neuroinflammatory responses such as microglial and astroglial cell activation. Neurological deficits were observed during the acute phase of injury followed by a recovery, then by a delayed onset of profound motor behavior impairment, reminiscent of the delayed clinical onset of motor system impairments observed in humans. Interleukin-1 receptor antagonist (IL-1ra) reduced the extent of brain lesions confirming the involvement of IL-1β response in their pathophysiology.

Conclusion

In rat pups at a neurodevelopmental age corresponding to full-term human newborns, a systemic pre-exposure to a pathogen component amplified HI-induced mortality and morbidities that are relevant to human pathology. Neuronal cells were the first cells to produce IL-1β in LPS + HI-exposed full-term brains. Such IL-1β production might be responsible for neuronal self-injuries via well-described neurotoxic mechanisms such as IL-1β-induced nitric oxide production, or IL-1β-dependent exacerbation of excitotoxic damage.
A physiologically-based flow network model for hepatic drug elimination II: variable lattice lobule models
Authors: Rezania Vahid , Marsh Rebeccah , Coombe Dennis , Tuszynski Jack
Published: September 2013

We extend a physiologically-based lattice model for the transport and metabolism of drugs in the liver lobule (liver functional unit) to consider structural and spatial variability. We compare predicted drug concentration levels observed exiting the lobule with their detailed distribution inside the lobule, and indicate the role that structural variation has on these results. Liver zonation and its role on drug metabolism represent another aspect of structural inhomogeneity that we consider here. Since various liver diseases can be thought to produce such structural variations, our analysis gives insight into the role of disease on liver function and performance. These conclusions are based on the dominant role of convection in well-vascularized tissue with a given structure.
Evolution of clitellate phaosomes from rhabdomeric photoreceptor cells of polychaetes – a study in the leech Helobdella robusta (Annelida, Sedentaria, Clitellata)
Authors: Döring Carmen , Gosda Jasmin , Tessmar-Raible Kristin , Hausen Harald , Arendt Detlev , Purschke Günter
Published: September 2013

Introduction

In Annelida two types of photoreceptor cells (PRCs) are regarded as generally present, rhabdomeric and ciliary PRCs. In certain taxa, however, an additional type of PRC may occur, the so called phaosomal PRC. Whereas the former two types of PRCs are always organized as an epithelium with their sensory processes projecting into an extracellular cavity formed by the PRCs and (pigmented) supportive cells, phaosomes are seemingly intracellular vacuoles housing the sensory processes. Phaosomal PRCs are the only type of PRC found in one major annelid group, Clitellata. Several hypotheses have been put forward explaining the evolutionary origin of the clitellate phaosomes. To elucidate the evolution of clitellate PRC and eyes the leech Helobdella robusta, for which a sequenced genome is available, was chosen.

Results

TEM observations showed that extraocular and ocular PRCs are structurally identical. Bioinformatic analyses revealed predictions for four opsin genes, three of which could be amplified. All belong to the rhabdomeric opsin family and phylogenetic analyses showed them in a derived position within annelid opsins. Gene expression studies showed two of them expressed in the eye and in the extraocular PRCs. Polychaete eye-typic key enzymes for ommochromme and pterin shading pigments synthesis are not expressed in leech eyes.

Conclusions

By comparative gene-expression studies we herein provide strong evidence that the phaosomal PRCs typical of Clitellata are derived from the rhabdomeric PRCs characteristic for polychaete adult eyes. Thus, they represent a highly derived type of PRC that evolved in the stem lineage of Clitellata rather than another, primitive type of PRC in Metazoa. Evolution of these PRCs in Clitellata is related to a loss of the primary eyes and most of their photoreceptive elements except for the rhabdomeric PRCs. Most likely this happened while changing to an endobenthic mode of life. This hypothesis of PRC evolution is in accordance with a recently published phylogeny of Annelida based on phylogenomic data. The data provide a nice example how morphologically highly divergent light sensitive structures emerged from a standard type of photoreceptor cell.
Rapid emergence of a virulent PB2 E627K variant during adaptation of highly pathogenic avian influenza H7N7 virus to mice
Authors: de Jong Rineke MC , Stockhofe-Zurwieden Norbert , Verheij Eline S , de Boer-Luijtze Els A , Ruiter Saskia JM , de Leeuw Olav S , Cornelissen Lisette AHM
Published: September 2013

Background

Highly pathogenic avian influenza (HPAI) viruses pose a potential human health threat as they can be transmitted directly from infected poultry to humans. During a large outbreak of HPAI H7N7 virus among poultry in The Netherlands in 2003, bird to human transmission was confirmed in 89 cases, of which one had a fatal outcome.

Methods

To identify genetic determinants of virulence in a mammalian host, we passaged an avian H7N7/03 outbreak isolate in mouse lungs and evaluated the phenotype of the mouse-adapted variant in animal models and in vitro.

Results

Three passages in mouse lungs were sufficient to select a variant that was highly virulent in mice. The virus had a MLD50 that was >4.3 logs lower than that of its non-lethal parental virus. Sequence analysis revealed a single mutation at position 627 in PB2, where the glutamic acid was changed to a lysine (E627K). The mouse-adapted virus has this mutation in common with the fatal human case isolate. The virus remained highly pathogenic for chickens after its passage in mice. In ferrets, the mouse-adapted virus induced more severe disease, replicated to higher titers in the lower respiratory tract and spread more efficiently to systemic organs compared with the parental virus. In vitro, the PB2 E627K mutation had a promoting effect on virus propagation in mammalian, but not in avian cells.

Conclusions

Our results show that the E627K mutation in PB2 alone can be sufficient to convert an HPAI H7N7 virus of low virulence to a variant causing severe disease in mice and ferrets. The rapid emergence of the PB2 E627K mutant during mouse adaptation and its pathogenicity in ferrets emphasize the potential risk of HPAI H7N7 viruses for human health.
Intensity modulated radiotherapy of upper abdominal malignancies: dosimetric comparison with 3D conformal radiotherapy and acute toxicity
Authors: Nour Alaa Ahmad , Alaradi Aziz , Mohamed Adel , Altuwaijri Saleh , Rudat Volker
Published: September 2013

Background

The goal of this study was to assess a possible dosimetric advantage of intensity modulated radiotherapy (IMRT) of upper abdominal malignancies compared to three-dimensional conformal radiotherapy (3DCRT), and to assess the impact of IMRT on acute toxicity.

Methods

Thirty-one unselected consecutive patients with upper abdominal malignancies were treated with definitive (n =16) or postoperative (n =15) IMRT. Twenty-one patients (67.7%) received concomitant chemotherapy. 3DCRT plans were generated for comparison, and analysis of variance (ANOVA) for repeated measurements was used to test for significant difference of dosimetric parameters. Acute toxicity was assessed weekly using the Common Terminology Criteria for Adverse Events (CTCAE) grading scale.

Results

IMRT plans showed a small but statistically significant improvement of the conformity index compared to 3DCRT plans (difference (95% confidence interval), -0.06 (−0.109 to-0.005); p = 0.03). The homogeneity index was not significantly improved (p = 0.10). A significantly reduced high dose volume on cost of a significantly increased low dose volume was observed for the kidneys. The acute toxicity appeared to be less than commonly reported for corresponding patients treated with 3DCRT. No patient developed grade 3 or 4 non-hematological acute toxicity, and the most common grade 2 toxicity was vomiting (9.7%).

Conclusions

IMRT offers the potential of a clinically relevant dosimetric advantage compared to 3DCRT in terms of a reduced acute toxicity. Further optimization of the radiotherapy technique and more clinical trials are required before IMRT is routinely used for upper abdominal malignancies.
The role of preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis
Authors: Lao Lifeng , Weng Xisheng , Qiu Guixing , Shen Jianxiong
Published: September 2013

Background

The patients with extremely severe spinal deformity are commonly considered high-risk candidates for surgical treatment because of their underlying lung disease. Currently, little has been reported about the postoperative pulmonary complication events in this population. This retrospective study sought to evaluate preoperative pulmonary function tests in the surgical treatment of extremely severe scoliosis.

Methods

Preoperative forced vital capacity (FVC), FVC ratio, forced expiratory volume at the end of the first second (FEV1), FEV1 ratio, peak expiratory flow (PEF), and PEF ratio were performed and evaluated on 60 patients with extremely severe scoliosis (coronary main Cobb angle ≥100°).

Results

Among the 60 patients, 11 (18.3%), 13 (21.7%), and 22 (36.7%) had severe, moderate, and mild pulmonary dysfunction, respectively. Compared with the moderate and mild scoliosis groups, significant differences were observed in Cobb, FVC, FVC ratio, FEV1, FEV1 ratio, and PEF ratio in the extremely severe scoliosis group. Various postoperative pulmonary complications occurred in nine cases (15%). Patients with severe or moderate dysfunction as measured by the FVC ratio had a higher incidence of postoperative pulmonary complications. A transthoracic procedure was not related to postoperative pulmonary complications, but thoracoplasty significantly increased the incidence of postoperative pulmonary complications (P < 0.001, OR = 20, 95% CI = 3.45–115.97).

Discussion

Pulmonary function was impaired in extremely severe scoliosis. Patients with severe restrictive pulmonary dysfunction had a higher incidence of postoperative pulmonary complications. Thoracoplasty was an important risk factor in the prediction of postoperative pulmonary complications.
Risk factors and mortality after elective and emergent laparatomies for oncological procedures in 899 patients in the intensive care unit: a retrospective observational cohort study
Authors: Mallol Montserrat , Sabaté Antoni , Dalmau Antonia , Koo Maylin
Published: September 2013

Background

Abdominal surgeries for cancer are associated with postoperative complications and mortality. A view of the success of anaesthetic, surgical and critical care can be gained by analyzing factors associated with mortality in patients admitted to intensive care units (ICUs). The objective of this study was to identify the postoperative mortality rate and the causes of perioperative death in high-risk patients after abdominal surgery for cancer. A secondary objective was to explore possible risk factors for death in scheduled and emergency surgeries, with a view to finding guidance on preventable risk factors.

Methods

An observational study, in a 12-bed surgical ICU of a tertiary hospital. Patients admitted after abdominal surgery for cancer to the ICU for more than 24 hours’ care were included from January 1, 2008–December 31, 2009. Data were extracted from the minimum basic dataset. The main outcome considered was 90-day mortality.

Results

Of 899 patients included, 80 (8.9%) died. Seven died within 48 hours of surgery, 18 died between 2 and 7 days, and 55 died after 7 days. Non-survivors were older and had more respiratory comorbidity, chronic liver disease, metastasis, and underwent more palliative procedures. 112 patients underwent emergency surgery; mortality in these patients for resection surgery was 32.5%; in the 787 patients who underwent scheduled surgery, mortality was 4.7% for resection procedures. The estimated odds ratios (95% confidence interval) of preoperative patient factors in emergency surgery confirmed a negative association between survival and older age 0.96 (0.91–1), the presence of respiratory comorbidity 0.14 (0.02–0.77) and metastasis 0.18 (0.05–0.6). After scheduled surgery, survival was negatively associated with age 0.93 (0.90–0.96) and chronic liver disease 0.40 (0.17–0.91). Analysis of complications after emergency surgery also indicated a negative association with sepsis 0.03 (0.003–0.32), respiratory events 0.043 (0.011–0.17) and cardiac events 0.11 (0.027–0.45); after scheduled surgery, respiratory 0.03 (0.01–0.08) and cardiac 0.11 (0.02–0.45) events, renal failure 0.02 (0.006–0.14) and neurological events 0.06 (0.007–0.5).

Conclusions

As most deaths occurred after discharge from the ICU, postoperative sepsis, respiratory and cardiac events should be watched carefully on the ward.
Verbal Final Exam in Introductory Biology Yields Gains in Student Content Knowledge and Longitudinal Performance
Authors: Luckie Douglas B. , Rivkin Aaron M. , Aubry Jacob R. , Marengo Benjamin J. , Creech Leah R. , Sweeder Ryan D.
Published: September 2013

We studied gains in student learning over eight semesters in which an introductory biology course curriculum was changed to include optional verbal final exams (VFs). Students could opt to demonstrate their mastery of course material via structured oral exams with the professor. In a quantitative assessment of cell biology content knowledge, students who passed the VF outscored their peers on the medical assessment test (MAT), an exam built with 40 Medical College Admissions Test (MCAT) questions (66.4% [n = 160] and 62% [n = 285], respectively; p < 0.001);. The higher-achieving students performed better on MCAT questions in all topic categories tested; the greatest gain occurred on the topic of cellular respiration. Because the VF focused on a conceptually parallel topic, photosynthesis, there may have been authentic knowledge transfer. In longitudinal tracking studies, passing the VF also correlated with higher performance in a range of upper-level science courses, with greatest significance in physiology, biochemistry, and organic chemistry. Participation had a wide range but not equal representation in academic standing, gender, and ethnicity. Yet students nearly unanimously (92%) valued the option. Our findings suggest oral exams at the introductory level may allow instructors to assess and aid students striving to achieve higher-level learning.
It's Money! Real-World Grant Experience through a Student-Run, Peer-Reviewed Program
Authors: Dumanis Sonya B. , Ullrich Lauren , Washington Patricia M. , Forcelli Patrick A.
Published: September 2013

Grantsmanship is an integral component of surviving and thriving in academic science, especially in the current funding climate. Therefore, any additional opportunities to write, read, and review grants during graduate school may have lasting benefits on one's career. We present here our experience with a small, student-run grant program at Georgetown University Medical Center. Founded in 2010, this program has several goals: 1) to give graduate students an opportunity to conduct small, independent research projects; 2) to encourage graduate students to write grants early and often; and 3) to give graduate students an opportunity to review grants. In the 3 yr since the program's start, 28 applications have been submitted, 13 of which were funded for a total of $40,000. From funded grants, students have produced abstracts and manuscripts, generated data to support subsequent grant proposals, and made new professional contacts with collaborators. Above and beyond financial support, this program provided both applicants and reviewers an opportunity to improve their writing skills, professional development, and understanding of the grants process, as reflected in the outcome measures presented. With a small commitment of time and funding, other institutions could implement a program like this to the benefit of their graduate students.
Assessing the Life Science Knowledge of Students and Teachers Represented by the K–8 National Science Standards
Authors: Sadler Philip M. , Coyle Harold , Smith Nancy Cook , Miller Jaimie , Mintzes Joel , Tanner Kimberly , Murray John
Published: September 2013

We report on the development of an item test bank and associated instruments based on the National Research Council (NRC) K–8 life sciences content standards. Utilizing hundreds of studies in the science education research literature on student misconceptions, we constructed 476 unique multiple-choice items that measure the degree to which test takers hold either a misconception or an accepted scientific view. Tested nationally with 30,594 students, following their study of life science, and their 353 teachers, these items reveal a range of interesting results, particularly student difficulties in mastering the NRC standards. Teachers also answered test items and demonstrated a high level of subject matter knowledge reflecting the standards of the grade level at which they teach, but exhibiting few misconceptions of their own. In addition, teachers predicted the difficulty of each item for their students and which of the wrong answers would be the most popular. Teachers were found to generally overestimate their own students’ performance and to have a high level of awareness of the particular misconceptions that their students hold on the K–4 standards, but a low level of awareness of misconceptions related to the 5–8 standards.
Bioinformatics Education in High School: Implications for Promoting Science, Technology, Engineering, and Mathematics Careers
Authors: Kovarik Dina N. , Patterson Davis G. , Cohen Carolyn , Sanders Elizabeth A. , Peterson Karen A. , Porter Sandra G. , Chowning Jeanne Ting
Published: September 2013

We investigated the effects of our Bio-ITEST teacher professional development model and bioinformatics curricula on cognitive traits (awareness, engagement, self-efficacy, and relevance) in high school teachers and students that are known to accompany a developing interest in science, technology, engineering, and mathematics (STEM) careers. The program included best practices in adult education and diverse resources to empower teachers to integrate STEM career information into their classrooms. The introductory unit, Using Bioinformatics: Genetic Testing, uses bioinformatics to teach basic concepts in genetics and molecular biology, and the advanced unit, Using Bioinformatics: Genetic Research, utilizes bioinformatics to study evolution and support student research with DNA barcoding. Pre–post surveys demonstrated significant growth (n = 24) among teachers in their preparation to teach the curricula and infuse career awareness into their classes, and these gains were sustained through the end of the academic year. Introductory unit students (n = 289) showed significant gains in awareness, relevance, and self-efficacy. While these students did not show significant gains in engagement, advanced unit students (n = 41) showed gains in all four cognitive areas. Lessons learned during Bio-ITEST are explored in the context of recommendations for other programs that wish to increase student interest in STEM careers.
A Summer Academic Research Experience for Disadvantaged Youth
Authors: Kabacoff Cathryn , Srivastava Vasudha , Robinson Douglas N.
Published: September 2013

Internships are an effective way of connecting high school students in a meaningful manner to the sciences. Disadvantaged minorities have fewer opportunities to participate in internships, and are underrepresented in both science, technology, engineering, and mathematics majors and careers. We have developed a Summer Academic Research Experience (SARE) program that provides an enriching academic internship to underrepresented youth. Our program has shown that to have a successful internship for these disadvantaged youth, several issues need to be addressed in addition to scientific mentoring. We have found that it is necessary to remediate and/or fortify basic academic skills for students to be successful. In addition, students need to be actively coached in the development of professional skills, habits, and attitudes necessary for success in the workplace. With all these factors in place, these youths can become better students, compete on a more level playing field in their internships, and increase their potential of participating actively in the sciences in the future.
Correlation between MCAT Biology Content Specifications and Topic Scope and Sequence of General Education College Biology Textbooks
Authors: Rissing Steven W.
Published: September 2013

Most American colleges and universities offer gateway biology courses to meet the needs of three undergraduate audiences: biology and related science majors, many of whom will become biomedical researchers; premedical students meeting medical school requirements and preparing for the Medical College Admissions Test (MCAT); and students completing general education (GE) graduation requirements. Biology textbooks for these three audiences present a topic scope and sequence that correlates with the topic scope and importance ratings of the biology content specifications for the MCAT regardless of the intended audience. Texts for “nonmajors,” GE courses appear derived directly from their publisher's majors text. Topic scope and sequence of GE texts reflect those of “their” majors text and, indirectly, the MCAT. MCAT term density of GE texts equals or exceeds that of their corresponding majors text. Most American universities require a GE curriculum to promote a core level of academic understanding among their graduates. This includes civic scientific literacy, recognized as an essential competence for the development of public policies in an increasingly scientific and technological world. Deriving GE biology and related science texts from majors texts designed to meet very different learning objectives may defeat the scientific literacy goals of most schools’ GE curricula.
Th17 memory cells: live long and proliferate
Authors: McGeachy Mandy J
Published: September 2013

The development of immune memory is a double-edged sword, helping to maintain health by preventing repeated infections but also driving chronic inflammation when dysregulated. Th17 cells are now well-known as major drivers of autoimmune disease but also play roles in protective immune responses against pathogens. This mini-review will focus on the recent evidence for long-lived, robust Th17 memory cell populations in mouse models and humans, and their functional roles in mediating host protection and chronic disease states.
From the Social to the Political: 1920s Colonial Saigon as a “Space of Possibilities” In Vietnamese Consciousness
Authors: Peycam Philippe
Published: September 2013

A public political sphere, to exist, requires the convergence of phenomena primarily of socioeconomic and cultural nature. In early twentieth-century southern Vietnam, the emergence of new socially, economically, and culturally determined categories among the indigenous population in the context of modern colonial urbanism was an essential condition for the development of this culture of political diversity. This article describes the new forces brought about by the colonial regime — the imposition of a modern state apparatus, the introduction of French education, the opening of society to the global economy — all of which converged in the making of Saigon, the colonial metropolis. In the city, new forms of individual consciousness arose as a result, and with them, new practices of collective socialization. Fraternal and other voluntary associations would develop and lead to the emergence of a public political sphere, what Jürgen Habermas called a culture of open rational enquiry.