bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renewable Energy Needs in Developing Countries: Barriers That Can Be Solved With Engineering
Authors: Barger K. McCall , Mattson Christopher A. 
Published: April 2017

Access to electricity is one of the most essential requirements for development. Furthermore, the U.S. Energy Information Administration has predicted that growth in electricity use is projected to largely come from developing countries as defined by the Organization for Economic Cooperation and Development (OECD). However, the transition to clean energy is occurring too slowly in rural parts of developing countries. Renewable energy provides the opportunity for sustainable energy to be provided to those living in rural areas of developing countries, who have not had access to clean energy. Renewable energy technology is necessary because traditional measures of energy access are not able to address the deficiencies in the affordability, reliability, and other barriers associated with renewable energy distribution.
While there have been several successful rural electrification technologies in the past few years, sustainable technologies still have the potential to be unsuccessful if they fail to overcome the many barriers that stand in the way of energy progression in developing countries. Moreover, a product’s technical performance is not a sound indicator of how well that product will be adopted by users. This paper argues that technical and social barriers to renewable energy dissemination have not been surmounted due to a lack of innovation in terms of engineering solutions. Innovative “grid-free” engineering products can enable developing countries to avoid a possible industrial revolution while still growing their economy, since they are not hindered by an electricity grid. This paper identifies technical barriers to renewable energy development from the literature, and suggests possible innovations that can aid rural areas of developing countries in achieving electrification. The technology explored in this paper include super capacitors, a ground-air thermoelectric generator, and photovoltaic solar cells, which all have the potential to provide energy access to those living in less urbanized areas of developing countries.
Building Inclusive Undergraduate Teams
Authors: Barr Ryan , Pfeiffer Claire , Dillon Heather , Doughty Timothy 
Published: April 2017

This paper describes a research project to encourage and enhance formation of undergraduate project teams with a focus on inclusivity. The project was developed by a team of undergraduate students working with a pair of engineering faculty. A survey including questions about team study groups was prepared and used to gather data about how engineering student teams are formed and how students perceive teams at different points as they progress through the curriculum. Interviews with junior/senior level students were filmed and the footage was used to build a composite video to serve as motivation to first and second year students. The video was presented in a second year dynamics class and the students were surveyed to understand the effectiveness of the intervention.
The survey results indicate that nearly half of all junior/senior engineering students feel ethically charged to include other students in a study group, while only 32% of second year students feel ethically charged. This research is part of a larger effort to develop methods for merging engineering ethics and professionalism in the mechanical engineering curriculum.
Enhanced Klebsiella pneumoniae Carbapenemase Expression from a Novel Tn
4401
Deletion
Authors: Cheruvanky Anita , Stoesser Nicole , Sheppard Anna E. , Crook Derrick W. , Hoffman Paul S. , Weddle Erin , Carroll Joanne , Sifri Costi D. , Chai Weidong , Barry Katie , Ramakrishnan Girija , Mathers Amy J. 
Published: April 2017

ABSTRACT

The
Klebsiella pneumoniae
carbapenemase gene (
bla
KPC
) is typically located within mobile transposon Tn
4401
. Enhanced KPC expression has been associated with deletions in the putative promoter region upstream of
bla
KPC
. Illumina sequences from
bla
KPC
-positive clinical isolates from a single institution were mapped to a Tn
4401
b reference sequence, which carries no deletions. The novel isoform Tn
4401
h (188-bp deletion [between
istB
and
bla
KPC
]) was present in 14% (39/281) of clinical isolates. MICs showed that
Escherichia coli
strains containing plasmids with Tn
4401
a and Tn
4401
h were more resistant to meropenem (≥16 and ≥16, respectively), ertapenem (≥8 and 4, respectively), and cefepime (≥64 and 4, respectively) than
E. coli
strains with Tn
4401
b (0.5, ≤0.5, and ≤1, respectively). Quantitative real-time PCR (qRT-PCR) demonstrated that Tn
4401
a had a 16-fold increase and Tn
4401
h a 4-fold increase in
bla
KPC
mRNA levels compared to the reference Tn
4401
b. A
lacZ
reporter plasmid was used to test the activity of the promoter regions from the different variants, and the results showed that the Tn
4401
a and Tn
4401
h promoter sequences generated higher β-galactosidase activity than the corresponding Tn
4401
b sequence. Further dissection of the promoter region demonstrated that putative promoter P1 was not functional. The activity of the isolated P2 promoter was greatly enhanced by inclusion of the P1-P2 intervening sequence. These studies indicated that gene expression could be an important consideration in understanding resistance phenotypes predicted by genetic signatures in the context of sequencing-based rapid diagnostics.
Antimicrobial Effects of β-Lactams on Imipenem-Resistant Ceftazidime-Susceptible Pseudomonas aeruginosa
Authors: Wi Yu Mi , Choi Ji-Young , Lee Ji-Young , Kang Cheol-In , Chung Doo Ryeon , Peck Kyong Ran , Song Jae-Hoon , Ko Kwan Soo 
Published: April 2017

ABSTRACT

We studied the resistance mechanism and antimicrobial effects of β-lactams on imipenem-resistant
Pseudomonas aeruginosa
isolates that were susceptible to ceftazidime as detected by time-kill curve methods. Among 215
P. aeruginosa
isolates from hospitalized patients in eight hospitals in the Republic of Korea, 18 isolates (23.4% of 77 imipenem-resistant isolates) were imipenem resistant and ceftazidime susceptible. Multilocus sequence typing revealed diverse genotypes, which indicated independent emergence. These 18 isolates were negative for carbapenemase genes. All 18 imipenem-resistant ceftazidime-susceptible isolates showed decreased mRNA expression of
oprD
, and overexpression of
mexB
was observed in 13 isolates. In contrast, overexpression of
ampC
,
mexD
,
mexF
, or
mexY
was rarely found. Time-kill curve methods were applied to three selected imipenem-resistant ceftazidime-susceptible isolates at a standard inoculum (5 × 10
5
CFU/ml) or at a high inoculum (5 × 10
7
CFU/ml) to evaluate the antimicrobial effects of β-lactams. Inoculum effects were detected for all three β-lactam antibiotics, ceftazidime, cefepime, and piperacillin-tazobactam, against all three isolates. The antibiotics had significant killing effects in the standard inoculum, but no effects in the high inoculum were observed. Our results suggest that β-lactam antibiotics should be used with caution in patients with imipenem-resistant ceftazidime-susceptible
P. aeruginosa
infection, especially in high-inoculum infections such as endocarditis and osteomyelitis.
Molecular Characterization of Escherichia coli Isolates Carrying
mcr-1
,
fosA3
, and Extended-Spectrum-β-Lactamase Genes from Food Samples in China
Authors: Liu Xiaobo , Li Ruichao , Zheng Zhiwei , Chen Kaichao , Xie Miaomiao , Chan Edward Wai-Chi , Geng Shu , Chen Sheng 
Published: April 2017

ABSTRACT

This study surveyed the prevalence of
mcr-1
in extended-spectrum-β-lactamase (ESBL)-producing
Escherichia coli
strains of food origin in China and identified strains that carried
mcr-1
,
fosA3
, and ESBL genes, which were carried in various plasmids. The
mcr-1
and ESBL genes could be cotransferred by one or more types of plasmids. The presence of these multidrug-resistant
E. coli
strains in food products might pose a huge threat to public health.
Lung Tissue Concentrations of Pyrazinamide among Patients with Drug-Resistant Pulmonary Tuberculosis
Authors: Kempker Russell R. , Heinrichs M. Tobias , Nikolaishvili Ketino , Sabulua Irina , Bablishvili Nino , Gogishvili Shota , Avaliani Zaza , Tukvadze Nestani , Little Brent , Bernheim Adam , Read Timothy D. , Guarner Jeannette , Derendorf Hartmut , Peloquin Charles A. , Blumberg Henry M. , Vashakidze Sergo 
Published: April 2017

ABSTRACT

Improved knowledge regarding the tissue penetration of antituberculosis drugs may help optimize drug management. Patients with drug-resistant pulmonary tuberculosis undergoing adjunctive surgery were enrolled. Serial serum samples were collected, and microdialysis was performed using
ex vivo
lung tissue to measure pyrazinamide concentrations. Among 10 patients, the median pyrazinamide dose was 24.7 mg/kg of body weight. Imaging revealed predominant lung lesions as cavitary (
n
= 6 patients), mass-like (
n
= 3 patients), or consolidative (
n
= 1 patient). On histopathology examination, all tissue samples had necrosis; eight had a pH of ≤5.5. Tissue samples from two patients were positive for
Mycobacterium tuberculosis
by culture (pH 5.5 and 7.2). All 10 patients had maximal serum pyrazinamide concentrations within the recommended range of 20 to 60 μg/ml. The median lung tissue free pyrazinamide concentration was 20.96 μg/ml. The median tissue-to-serum pyrazinamide concentration ratio was 0.77 (range, 0.54 to 0.93). There was a significant inverse correlation between tissue pyrazinamide concentrations and the amounts of necrosis (
R
= −0.66,
P
= 0.04) and acid-fast bacilli (
R
= −0.75,
P
= 0.01) identified by histopathology. We found good penetration of pyrazinamide into lung tissue among patients with pulmonary tuberculosis with a variety of radiological lesion types. Our tissue pH results revealed that most lesions had a pH conducive to pyrazinamide activity. The tissue penetration of pyrazinamide highlights its importance in both drug-susceptible and drug-resistant antituberculosis treatment regimens.
Evolutionary Origin of the Staphylococcal Cassette Chromosome
mec
(SCC
mec
)
Authors: Rolo Joana , Worning Peder , Nielsen Jesper Boye , Bowden Rory , Bouchami Ons , Damborg Peter , Guardabassi Luca , Perreten Vincent , Tomasz Alexander , Westh Henrik , de Lencastre Hermínia , Miragaia Maria 
Published: April 2017

ABSTRACT

Several lines of evidence indicate that the most primitive staphylococcal species, those of the
Staphylococcus sciuri
group, were involved in the first stages of evolution of the staphylococcal cassette chromosome
mec
(SCC
mec
), the genetic element carrying the β-lactam resistance gene
mecA
. However, many steps are still missing from this evolutionary history. In particular, it is not known how
mecA
was incorporated into the mobile element SCC prior to dissemination among
Staphylococcus aureus
and other pathogenic staphylococcal species. To gain insights into the possible contribution of several species of the
Staphylococcus sciuri
group to the assembly of SCC
mec
, we sequenced the genomes of 106 isolates, comprising
S. sciuri
(
n
= 76),
Staphylococcus vitulinus
(
n
= 18), and
Staphylococcus fleurettii
(
n
= 12) from animal and human sources, and characterized the native location of
mecA
and the SCC insertion site by using a variety of comparative genomic approaches. Moreover, we performed a single nucleotide polymorphism (SNP) analysis of the genomes in order to understand SCC
mec
evolution in relation to phylogeny. We found that each of three species of the
S. sciuri
group contributed to the evolution of SCC
mec
:
S. vitulinus
and
S. fleurettii
contributed to the assembly of the
mec
complex, and
S. sciuri
most likely provided the mobile element in which
mecA
was later incorporated. We hypothesize that an ancestral SCC
mec
III cassette (an element carried by one of the most epidemic methicillin-resistant
S. aureus
clones) originated in
S. sciuri
possibly by a recombination event in a human host or a human-created environment and later was transferred to
S. aureus
.
Delamanid Kills Dormant Mycobacteria
In Vitro
and in a Guinea Pig Model of Tuberculosis
Authors: Chen Xiuhao , Hashizume Hiroyuki , Tomishige Tatsuo , Nakamura Izuru , Matsuba Miki , Fujiwara Mamoru , Kitamoto Ryuki , Hanaki Erina , Ohba Yoshio , Matsumoto Makoto 
Published: April 2017

ABSTRACT

Tuberculosis (TB) treatment is long and requires multiple drugs, likely due to various phenotypes of TB bacilli with variable drug susceptibilities. Drugs with broad activity are urgently needed. This study aimed to evaluate delamanid's activity against growing or dormant bacilli
in vitro
as well as
in vivo
. Cultures of
Mycobacterium bovis
BCG Tokyo under aerobic and anaerobic conditions were used to study the activity of delamanid against growing and dormant bacilli, respectively. Delamanid exhibited significant bactericidal activity against replicating and dormant bacilli at or above concentrations of 0.016 and 0.4 mg/liter, respectively. To evaluate delamanid's antituberculosis activity
in vivo
, we used a guinea pig model of chronic TB infection in which the lung lesions were similar to those in human TB disease. In the guinea pig TB model, a daily dose of 100 mg delamanid/kg of body weight for 4 or 8 weeks demonstrated strong bactericidal activity against
Mycobacterium tuberculosis
. Importantly, histological examination revealed that delamanid killed TB bacilli within hypoxic lesions of the lung. The combination regimens containing delamanid with rifampin and pyrazinamide or delamanid with levofloxacin, ethionamide, pyrazinamide, and amikacin were more effective than the standard regimen (rifampin, isoniazid, and pyrazinamide). Our data show that delamanid is effective in killing both growing and dormant bacilli
in vitro
and in the guinea pig TB model. Adding delamanid to current TB regimens may improve treatment outcomes, as demonstrated in recent clinical trials with pulmonary multidrug-resistant (MDR) TB patients. Delamanid may be an important drug for consideration in the construction of new regimens to shorten TB treatment duration.
Results from a 13-Year Prospective Cohort Study Show Increased Mortality Associated with Bloodstream Infections Caused by Pseudomonas aeruginosa Compared to Other Bacteria
Authors: Thaden Joshua T. , Park Lawrence P. , Maskarinec Stacey A. , Ruffin Felicia , Fowler Vance G. , van Duin David 
Published: April 2017

ABSTRACT

The impact of bacterial species on outcome in bloodstream infections (BSI) is incompletely understood. We evaluated the impact of bacterial species on BSI mortality, with adjustment for patient, bacterial, and treatment factors. From 2002 to 2015, all adult inpatients with monomicrobial BSI caused by
Staphylococcus aureus
or Gram-negative bacteria at Duke University Medical Center were prospectively enrolled. Kaplan-Meier curves and multivariable Cox regression with propensity score models were used to examine species-specific bacterial BSI mortality. Of the 2,659 enrolled patients, 999 (38%) were infected with
S. aureus
, and 1,660 (62%) were infected with Gram-negative bacteria. Among patients with Gram-negative BSI,
Enterobacteriaceae
(81% [1,343/1,660]) were most commonly isolated, followed by non-lactose-fermenting Gram-negative bacteria (16% [262/1,660]). Of the 999
S. aureus
BSI isolates, 507 (51%) were methicillin resistant. Of the 1,660 Gram-negative BSI isolates, 500 (30%) were multidrug resistant. The unadjusted time-to-mortality among patients with Gram-negative BSI was shorter than that of patients with
S. aureus
BSI (
P
= 0.003), due to increased mortality in patients with non-lactose-fermenting Gram-negative BSI generally (
P
< 0.0001) and
Pseudomonas aeruginosa
BSI (
n
= 158) in particular (
P
< 0.0001). After adjustment for patient demographics, medical comorbidities, bacterial antibiotic resistance, timing of appropriate antibiotic therapy, and source control in patients with line-associated BSI,
P. aeruginosa
BSI remained significantly associated with increased mortality (hazard ratio = 1.435; 95% confidence interval = 1.043 to 1.933;
P
= 0.02).
P. aeruginosa
BSI was associated with increased mortality relative to
S. aureus
or other Gram-negative BSI. This effect persisted after adjustment for patient, bacterial, and treatment factors.
Clumping Factor B Promotes Adherence of Staphylococcus aureus to Corneocytes in Atopic Dermatitis
Authors: Fleury Orla M. , McAleer Maeve A. , Feuillie Cécile , Formosa-Dague Cécile , Sansevere Emily , Bennett Désirée E. , Towell Aisling M. , McLean W. H. Irwin , Kezic Sanja , Robinson D. Ashley , Fallon Padraic G. , Foster Timothy J. , Dufrêne Yves F. , Irvine Alan D. , Geoghegan Joan A. 
Published: April 2017

ABSTRACT

Staphylococcus aureus
skin infection is a frequent and recurrent problem in children with the common inflammatory skin disease atopic dermatitis (AD).
S. aureus
colonizes the skin of the majority of children with AD and exacerbates the disease. The first step during colonization and infection is bacterial adhesion to the cornified envelope of corneocytes in the outer layer, the stratum corneum. Corneocytes from AD skin are structurally different from corneocytes from normal healthy skin. The objective of this study was to identify bacterial proteins that promote the adherence of
S. aureus
to AD corneocytes.
S. aureus
strains from clonal complexes 1 and 8 were more frequently isolated from infected AD skin than from the nasal cavity of healthy children. AD strains had increased ClfB ligand binding activity compared to normal nasal carriage strains. Adherence of single
S. aureus
bacteria to corneocytes from AD patients
ex vivo
was studied using atomic force microscopy. Bacteria expressing ClfB recognized ligands distributed over the entire corneocyte surface. The ability of an isogenic ClfB-deficient mutant to adhere to AD corneocytes compared to that of its parent clonal complex 1 clinical strain was greatly reduced. ClfB from clonal complex 1 strains had a slightly higher binding affinity for its ligand than ClfB from strains from other clonal complexes. Our results provide new insights into the first step in the establishment of
S. aureus
colonization in AD patients. ClfB is a key adhesion molecule for the interaction of
S. aureus
with AD corneocytes and represents a target for intervention.
Practices and attitudes of doctors and patients to downward referral in Shanghai, China
Authors: Yu Wenya , Li Meina , Nong Xin , Ding Tao , Ye Feng , Liu Jiazhen , Dai Zhixing , Zhang Lulu 
Published: April 2017

ObjectivesIn China, the rate of downward referral is relatively low, as most people are unwilling to be referred from hospitals to community health systems (CHSs). The aim of this study was to explore the effect of doctors' and patients' practices and attitudes on their willingness for downward referral and the relationship between downward referral and sociodemographic characteristics.MethodsDoctors and patients of 13 tertiary hospitals in Shanghai were stratified through random sampling. The questionnaire surveyed their sociodemographic characteristics, attitudes towards CHSs and hospitals, understanding of downward referral, recognition of the community first treatment system, and downward referral practices and willingness. Descriptive statistics, χ2test and stepwise logistic regression analysis were employed for statistical analysis.ResultsOnly 20.8% (161/773) of doctors were willing to accept downward referrals, although this proportion was higher among patients (37.6%, 326/866). Doctors' willingness was influenced by education, understanding of downward referral, and perception of health resources in hospitals. Patients' willingness was influenced by marital status, economic factors and recognition of the community first treatment system. Well-educated doctors who do not consider downward referral would increase their workloads and those with a more comprehensive understanding of hospitals and downward referral process were more likely to make a downward referral decision. Single-injury patients fully recognising the community first treatment system were more willing to accept downward referral. Patients' willingness was significantly increased if downward referral was cost-saving. A better medical insurance system was another key factor for patients to accept downward referral decisions, especially for the floating population.ConclusionsTo increase the rate of downward referral, the Chinese government should optimise the current referral system and conduct universal publicity for downward referral. Doctors and patients should promote understandings of downward referral. Hospitals should realise the necessity of downward referral, effectively reduce workloads and provide continuing education for doctors. Increasing monetary reimbursement is urgent, as is improving the medical insurance system.
Association between rhinovirus wheezing illness and the development of childhood asthma: a meta-analysis
Authors: Liu Lu , Pan Yilin , Zhu Yanting , Song Yang , Su Xiaofan , Yang Lan , Li Manxiang 
Published: April 2017

ObjectiveThe relation between early-life rhinovirus (RV) wheezing illness and later onset of wheezing/asthma remains a subject of debate. Therefore, we conducted this meta-analysis to evaluate the association between RV wheezing illness in the first 3 years of life and the subsequent development of wheezing/asthma.DesignSystematic review and meta-analysis.MethodsThe PubMed, EMBASE, Web of Science, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases were systematically searched for studies published between 1988 and February 2017, and additional studies were found by searching reference lists of relevant articles. 2 reviewers independently extracted data and assessed the quality of each study. Results were pooled using fixed-effect models or random-effects models as appropriate.ResultsThe meta-analysis included 15 original articles which met the criteria, while 10 articles reported the results of 4 longitudinal cohort studies with different follow-up periods. RV wheezing illness in the first 3 years of life was associated with an increased risk of wheezing/asthma in later life (relative risk (RR)=2.00, 95% CI 1.62 to 2.49, p<0.001). In subgroup analysis by age at follow-up, the association still remained significant in <10 years (RR=2.02, 95% CI 1.70 to 2.39, p<0.001) and ≥10 years (RR=1.92, 95% CI 1.36 to 2.72, p<0.001).ConclusionsThe meta-analysis suggests an association between RV-induced wheezing in the first 3 years of life and the subsequent development of wheezing/asthma. Large-scale and well-designed studies that adequately address concerns for potential confounding factors are required to validate the risk identified in the current meta-analysis.