bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of ventilation-perfusion mismatching in mechanically ventilated patients
Authors: Ferrer M , Zavala E , Diaz O , Roca J , Wagner PD , Rodriguez-Roisin R
Published: November 2002

The multiple inert gas elimination technique (MIGET) is a robust tool to assess both ventilation-perfusion (V'A/Q') distributions and the role of extrapulmonary factors determining arterial oxygenation during spontaneous breathing and in mechanically ventilated patients. Mixed expired gas sampling used in the MIGET is most often obtained from a 10-L mixing box (10L-MB) placed in the expiratory side of the ventilator circuit. Consequently, a considerable increase in the compression volume (Vc) would be expected which, in turn, can give rise to potential errors in the estimation of the effective tidal volume delivered to the patient. The effects of the 10L-MB on the Vc were compared with those produced by a newly designed 1-L, mixing box (IL-MB). At a given peak pressure (Ppeak) within the ventilator circuit, the Vc generated by the 10L-MB was about six-times higher than that produced by the 1L-MB. At a Ppeak =50 cmH2O, the Vc were 377 mL (10L-MB) and 67 mL (1L-MB) (p<0.001). In six patients, the mixed expired partial pressures of the six inert gases simultaneously collected from the two mixing boxes fell on the identity line. V'A/Q' distributions recovered using each of the two mixing boxes were equivalent. With the IL-MB, the effects of different positive end-expiratory pressure levels (0, 6 and 12 cmH2O) on Vc and arterial carbon dioxide tension were negligible. In conclusion, the new 1-L mixing box provides efficient gas mixing and substantially decreases the compression volume. It is, therefore, recommended when studies requiring mixed expired gas are performed in ventilated patients.
Pulmonary hypertension in high-altitude chronic hypoxia: response to nifedipine
Authors: Antezana AM , Antezana G , Aparicio O , Noriega I , Velarde FL , Richalet JP
Published: November 2002

Permanent residents at high altitude may develop excessive polycythaemia (H-Hb) and pulmonary hypertension, which often leads to cardiac failure. Inhibitors of calcium channels have been shown to reverse pulmonary hypertension in respiratory diseases and in primary pulmonary hypertension, but their efficiency has not been evaluated in high-altitude-induced pulmonary hypertension. Systolic pulmonary arterial pressure (Ppa) was studied by Doppler echocardiography, at rest and after sublingual nifedipine, in 31 asymptomatic residents at 3,600 m. Individuals were separated into two groups according to resting Ppa: a group with low Ppa (< or =4.7 kPa, n=17) and a group with high Ppa (>4.7 kPa, n=14). Individuals were also split into two groups according to haemoglobin (Hb) concentration: a normocythaemic (L-Hb) group ([Hb] < or =180 g.L(-1), n=17) and a H-Hb group ([Hb] >180 g.L.(-1), n=14). No significant difference in Ppa was observed between the L-Hb and H-Hb groups. There was no correlation between [Hb] and Ppa. Nifedipine induced a decrease of >20% in Ppa in two-thirds of the subjects. This response was correlated with higher levels of basal Ppa (p<0.001) and was inversely correlated with age in the L-Hb group (p<0.05). Pulmonary vasoreactivity to nifedipine was independent of the degree of H-Hb. Pulmonary hypertension secondary to chronic altitude hypoxia may be reversible, despite a possible remodelling of the pulmonary arterioles.
Single-breath method for assessing the viscoelastic properties of the respiratory system
Authors: Antonaglia V , Grop A , Demanins P , Beltrame F , Lucangelo U , Peratoner A , De Simoni L , Gullo A , Milic-Emili J
Published: November 2002

In order to explain the time dependency of resistance and elastance of the respiratory system, a linear viscoelastic model (Maxwell body) has been proposed. In this model the maximal viscoelastic pressure (Pvisc.max) developed within the tissues of the lung and chest wall at the end of a constant-flow (V') inflation of a given time (tI) is given by: Pvisc,max = R2V'(1-e(-tI/tau2), where R2 and tau2 are, respectively, the resistance and time constant of the Maxwell body. After rapid airway occlusion at t1, tracheal pressure (Ptr) decays according to the following function: Ptr(t) = Pvisc(t) + Prs,st = Pvisc,max(etocc/tau2)+ Prs,st, where tocc/is time after occlusion and Prs,st is static re-coil pressure of the respiratory system. By fitting Ptr after occlusion to this equation, tau2 and Pvisc,max are obtained. Using these values, together with the V' and tI pertaining to the constant-flow inflation preceding the occlusion, R2 can be calculated from the former equation. Thus, from a single breath, the constants tau2, R2 and E2 (R2/tau2) can be obtained. This method was used in 10 normal anaesthetized, paralysed, mechanically ventilated subjects and six patients with acute lung injury. The results were reproducible in repeated tests and similar to those obtained from the same subjects and patients with the time-consuming isoflow, multiple-breath method described previously.
Neutrophil serine proteinases and defensins in chronic obstructive pulmonary disease: effects on pulmonary epithelium
Authors: Hiemstra PS , van Wetering S , Stolk J
Published: November 2002

Neutrophils have the capacity to accumulate in high numbers in the lung during infection and inflammation. Because they play an important role in host defence against infection, but may also cause tissue injury, these cells are thought to be involved in the pathogenesis of various inflammatory lung disorders, including chronic bronchitis and chronic obstructive pulmonary disease. Neutrophil products that may mediate tissue injury at sites of neutrophil-dominated inflammation include the neutrophil serine proteinases elastase, cathepsin G and proteinase 3, and the nonenzymatic defensins. One of the targets of the neutrophil is the lung epithelium, and in vitro studies have revealed that both the serine proteinases and neutrophil defensins markedly affect the integrity of the epithelial layer, decrease the frequency of ciliary beat, increase the secretion of mucus, and induce the synthesis of epithelium-derived mediators that may influence the amplification and resolution of neutrophil-dominated inflammation. Both neutrophil elastase and defensins induce the release of the neutrophil chemoattractant chemokine interleukin-8 from respiratory epithelial cells. The alpha1-proteinase inhibitor (alpha1-PI) is a well-characterized inhibitor of neutrophil elastase, that also blocks the cytotoxic and stimulatory activity of defensins towards epithelial cells. The elastase inhibitory activity of alpha1-PI is also abrogated by the binding of defensins to this inhibitor. Incubation of epithelial cells with neutrophil defensins in combination with either elastase or cathepsin G resulted in decreased effects on the epithelial cells compared with those observed when the cells were incubated with defensins, elastase or cathepsin G separately. These results suggest that neutrophil defensins and serine proteinases cause injury and stimulate epithelial cells to produce chemokines that attract more neutrophils to the site of inflammation. The effects of neutrophil defensins and serine proteinases on epithelial cells appear to be restricted by proteinase inhibitors and by inhibitory interactions between these sets of neutrophil granule proteins.
Systemic vasculitis in a patient with small-cell neuroendocrine bronchial cancer
Authors: Ponge T , Boutoille D , Moreau A , Germaud P , Dabouis G , Baranger T , Barrier J
Published: November 2002

A 75-yr-old male hospitalized for vascular purpura with joint pain had a medical history of polymyalgia rheumatica. A generalized oedematous syndrome occurred and the patient also presented with haemoptysis and complained of transient paraesthesia of the hands and feet. Renal biopsy showed lesions of focal segmental proliferative glomerulonephritis associated with a few cellular crescents. Lung biopsy showed small-cell neuroendocrine carcinoma. After the first course of chemotherapy signs of vasculitis disappeared. Small-cell neuroendocrine carcinomas, which represent 25% of all lung cancers, have numerous paraneoplastic (especially neurological) extrapulmonary manifestations. Disseminated vasculitis has never been described with this type of cancer, whereas nonsmall-cell carcinomas are associated essentially with cutaneous vasculitis or purpura rheumatica. In the case reported here, anticancer chemotherapy allowed vasculitic manifestations to be treated.
Chylothorax or leakage of total parenteral nutrition?
Authors: Wolthuis A , Landewe RB , Theunissen PH , Westerhuis LW
Published: November 2002

The diagnosis chylothorax is based on a chemical analysis of the pleural effusion. According to the literature, this analysis can be rather straightforward, comprising measurements of triglycerides, chylomicrons, and cholesterol. In this report we present an autopsy case that alerted us to interpret these results critically. Although the laboratory tests of the pleural effusion in this patient with parenteral nutrition suggested chylothorax, additional tests (potassium (11.3 mmol.L(-1)) and glucose (128 mmol.L(-1)) proved otherwise. Comparison of the pleural effusion analysis and the content of the parenteral nutrition led to the final conclusion that the effusion was due to a leakage of parenteral nutrition instead of chylothorax. We therefore suggest adding glucose and potassium measurements to the biochemical work-up of a patient under suspicion of chylothorax.
Analyzing Defects in the Caenorhabditis elegans Nervous System Using Organismal and Cell Biological Approaches
Authors: Guziewicz Megan , Vitullo Toni , Simmons Bethany , Kohn Rebecca Eustance
Published: November 2002

The goal of this laboratory exercise is to increase student understanding of the impact of nervous system function at both the organismal and cellular levels. This inquiry-based exercise is designed for an undergraduate course examining principles of cell biology. After observing the movement of Caenorhabditis elegans with defects in their nervous system, students examine the structure of the nervous system to categorize the type of defect. They distinguish between defects in synaptic vesicle transport and defects in synaptic vesicle fusion with membranes. The synaptic vesicles are tagged with green fluorescent protein (GFP), simplifying cellular analysis. The expected outcome of this experiment is that students will better understand the concepts of vesicle transport, neurotransmitter release, GFP, and the relation between the nervous system and behavior.
Glucose Transport in Cultured Animal Cells: An Exercise for the Undergraduate Cell Biology Laboratory
Authors: Ledbetter Mary Lee S. , Lippert Malcolm J.
Published: November 2002

Membrane transport is a fundamental concept that undergraduate students of cell biology understand better with laboratory experience. Formal teaching exercises commonly used to illustrate this concept are unbiological, qualitative, or intricate and time consuming to prepare. We have developed an exercise that uses uptake of radiolabeled nutrient analogues by attachment-dependent animal cells cultured on multiwell trays. This system can readily be manipulated within a typical 3-h laboratory period to yield reproducible, biologically relevant, quantitative data regarding key aspects of membrane transport. Each 24-well tray of cultures allows a group of two to four students to compare eight conditions in triplicate. If different groups of students test different conditions or different types of cells, data can be shared for an even broader experience. The exercise is also readily adaptable for open-ended student projects. Here we illustrate the exercise measuring uptake of the nonmetabolizable glucose analogue [3H]-2-deoxy-d-glucose. Students successfully tested the effects of competing sugars, putative inhibitors of the GLUT1 transporter, and changes in cell physiology that might be expected to affect glucose transport in epithelial cells and fibroblasts. In this exercise students find the nutritional and medical implications of glucose transport and its regulation intriguing. They also learn to handle radioisotopes and cultured cells.
Biotechnology Apprenticeship for Secondary-Level Students: Teaching Advanced Cell Culture Techniques for Research
Authors: Lewis Jennifer R. , Kotur Mark S. , Butt Omar , Kulcarni Sumant , Riley Alyssa A. , Ferrell Nick , Sullivan Kathryn D. , Ferrari Mauro
Published: November 2002

The purpose of this article is to discuss small-group apprenticeships (SGAs) as a method to instruct cell culture techniques to high school participants. The study aimed to teach cell culture practices and to introduce advanced imaging techniques to solve various biomedical engineering problems. Participants designed and completed experiments using both flow cytometry and laser scanning cytometry during the 1-month summer apprenticeship. In addition to effectively and efficiently teaching cell biology laboratory techniques, this course design provided an opportunity for research training, career exploration, and mentoring. Students participated in active research projects, working with a skilled interdisciplinary team of researchers in a large research institution with access to state-of-the-art instrumentation. The instructors, composed of graduate students, laboratory managers, and principal investigators, worked well together to present a real and worthwhile research experience. The students enjoyed learning cell culture techniques while contributing to active research projects. The institution's researchers were equally enthusiastic to instruct and serve as mentors. In this article, we clarify and illuminate the value of small-group laboratory apprenticeships to the institution and the students by presenting the results and experiences of seven middle and high school participants and their instructors.
But Are They Learning? Getting Started in Classroom Evaluation
Authors: Dancy Melissa H. , Beichner Robert J.
Published: November 2002

There are increasing numbers of traditional biologists, untrained in educational research methods, who want to develop and assess new classroom innovations. In this article we argue the necessity of formal research over normal classroom feedback. We also argue that traditionally trained biologists can make significant contributions to biology pedagogy. We then offer some guidance to the biologist with no formal educational research training who wants to get started. Specifically, we suggest ways to find out what others have done, we discuss the difference between qualitative and quantitative research, and we elaborate on the process of gaining insights from student interviews. We end with an example of a project that has used many different research techniques.
Abrasive water jet machining of glass fibre metal laminates
Authors: Paul S , Hoogstrate A M , van Praag R
Published: November 2002

Glass fibre metal laminates (GFMLs) have been machined successfully with an abrasive water jet. The mechanism of material removal of the aluminium layer is by microcutting and plastic deformation similar to that observed in machining ductile materials. The glass fibres that are transverse to the direction of work travel are machined by microcutting and/or brittle fracture. The glass fibres that are parallel to the direction of work travel are removed in bulk by brittle feature. The fibres undergo substantial secondary erosion. No delamination has been observed except for the laminates with thinner aluminium layers.

The quality parameters associated with kerf, the taper quality parameter, the amount of burr formation, the straightness of the edge at the exit side, etc., correlate quite well with the cutting ability parameter. A quantitative relation, irrespective of the structure and build-up of the laminates, has been attempted between the taper quality parameter and the cutting ability parameter.
Development of an ultra-precision grinding system for machining optical aspheric components with a large depth—diameter ratio
Authors: Chen M , Zhao Q , Dong S , Li D
Published: November 2002

When grinding a large depth—diameter ratio aspheric part of high precision and high quality, the factors influencing surface roughness and profile accuracy of machined surfaces were theoretically analysed first. Afterwards the authors designed and manufactured the ultra-precision aspheric grinding system. The workpiece spindle, transverse guideway, longitudinal guideway and the grinder spindle are in aerostatic form. Turning accuracy of the workpiece spindle is 0.05 μm, the maximum rotational speed of the grinder is 80 000 r/min and the turning accuracy is 0.1 μm, and the resolution of linear displacement of the transverse and longitudinal guideway is 4.9 nm. The accuracy of the precise adjusting mechanism is 0.1 μm. The discharge principle of the dressing mechanism was developed in order to dress the diamond wheel. The ball-headed wheel has high profile accuracy after dressing. This mechanism solved the problem of on-position dressing of the case iron bonded diamond wheels and reduced the machining errors for aspheric surface components. Finally, grinding experiments for machining aspheric components were carried out. The grinding results indicated that the achieved profile accuracy is 0.3 μm and the surface roughness is less than 0.01 μm.
A comparative investigation of the efficacy of CO2 and high-power diode lasers for the forming of EN3 mild steel sheets
Authors: Lawrence J
Published: November 2002

A comparative investigation of the effectiveness of a high-power diode laser (HPDL) and a CO2 laser for the forming of thin-section EN3 mild steel sheet has been conducted. The buckling mechanism was identified as the laser forming mechanism responsible for induced bending. For both lasers it was found that the induced bending angles increased with an increasing number of irradiations and high laser powers, while decreasing as the traverse speed was increased. Also, it was apparent from the experimental results that the laser bending angle was only linearly proportional to the number of irradiations when the latter was small due to local material thickening along the bend edge with a high number of irradiations. Owing to the mild steel's greater beam absorption at the HPDL wavelength, larger bending angles were induced when using the HPDL. However, under certain conditions the performance of the CO2 laser in terms of induced bending angle was seen to approach that of the HPDL. Nevertheless, similar results between the two lasers were only achieved with increasing irradiations; thus it was concluded that the efficacy of the HPDL was higher than that of the CO2 laser insofar as it was more efficient. From graphical results and the employment of an analytical procedure, the laser line energy range in which accurate control of the HPDL bending of the mild steel sheets could be exercised efficiently was found to be 53 J/mm < P/ v < 78 J/mm, while for the CO2 laser the range was 61 J/mm < P/ v < 85 J/mm.
Comparison of environmental performance between plastic and steel fuel tanks
Authors: Tung C-y , Wang M H
Published: November 2002

Increasing awareness of environmental burdens has led companies and designers to initiate design for the environment (DFE) programmes, which consider the design of products from the ‘cradle to grave’ and is also known as ‘life-cycle design’. In this paper, the use of a novel environmental performance technique to be used at the early stage of product design is presented. This technique, which is to be used as a framework for green product design, is demonstrated in this paper by evaluating the environmental performance between plastic and steel fuel tanks. The fuel tank comparison can be divided into five steps. In the first four steps, a modified house of quality (HOQ) is used to analyse the performance of fuel tanks in terms of requirements of environmentally conscious design. The final step is an overall assessment that synthesizes the results from the previous four analyses. As a result, the comprehensive environmental effects in the whole life cycle of fuel tanks are captured in the early stage of design.
Static three-dimensional modelling of pneumatic tyres using the technique of element overlaying
Authors: Pelc J
Published: November 2002

The aim of the paper is to propose and verify an effective method for the realistic modelling of pneumatic tyres. A static, three-dimensional model of a pneumatic tyre, based on the finite element (FE) program MARC, is presented. The cord-rubber composite was modelled by overlaying the elements characterizing the cord and those representing incompressible rubber. A two-dimensional model was used to simulate the tyre mounting and inflation process. The model was then developed into a three-dimensional one. The displacements, radial stiffness and delamination stresses caused by the vertical load were determined. The shape of the tyre footprint and the pressure distribution in this zone were also predicted. Good correlation between measured and computed stiffness characteristics was observed. The proposed technique of element overlaying yields a tyre model that is numerically more stable than that using only orthotropic elements (very stiff cord merged with compliant rubber).
Dynamic effect of the non-rigid modified bicycle model
Authors: Wideberg J P
Published: November 2002

In this paper a method to add elastic effects to the classic ‘bicycle model’ for the simulation of the dynamic behaviour of vehicles is presented. The obtained results show that, in the simulations, dynamic effects such as lateral acceleration are more severe when non-rigid models of the vehicle frame are used. This work demonstrates that the modified bicycle model is a useful instrument to predict the response of a vehicle. At present, much effort is dedicated to simulation with rigid body dynamic programs. The proposed method offers an easy way to evaluate the dynamic effects in models with flexible frames. The elasticity of the frame has an important impact on the directional response (yaw gain and lateral velocity) of the vehicles. This method is useful for analysis from the behaviour of vehicles with modifications made after their manufacture. In the design phase the manufacturer has the suitable tools and the experience to avoid designing frames of low rigidity. Nevertheless, in the second-hand market it is very common for trucks and their structure to be modified. The change in rigidity of the frame could have considerable effects on directional stability and handling.
Improvement of fuel economy by shift speed control for a metal belt continuously variable transmission
Authors: Lee H , Kim H
Published: November 2002

In this paper, an algorithm to improve the fuel economy of a metal belt continuously variable transmission (CVT) vehicle by CVT shift speed control is suggested. By rearranging the CVT shift dynamic equation, it is found that the CVT shift speed depends on the line pressure as well as on the primary pressure. CVT shift speed maps are constructed to evaluate the influence of the line pressure on the shift speed. To obtain a target shift speed, an algorithm to calculate the line pressure is presented. In order to estimate the shift speed and the hydraulic loss, dynamic models of the line pressure control valve and the ratio control valve are obtained by considering the CVT shift dynamics and validated by experiments. It is found from the simulation results that fuel economy can be improved by 2 per cent in spite of the increased hydraulic loss due to the increased line pressure.
Use of an additive in biofuel to evaluate emissions, engine component wear and lubrication characteristics
Authors: Kalam M A , Majsuki H H
Published: November 2002

This paper presents the results of experiments carried out to evaluate the effect of adding an anticorrosion additive to blended biofuel and lubricating oil on emissions, engine component wear and lubrication characteristics. The blended biofuels consist of 7.5 and 15 per cent palm olein (PO) with ordinary diesel oil (OD). Pure OD was used for comparison purposes. Exhaust emission gases such as NOx, CO and hydrocarbons (HCs) were measured by an exhaust emission analyser for engine operation on 50 per cent throttle at speeds of 800-3600 r/min. To measure engine component wear and lubricating oil characteristics, the engine was operated at 50 per cent throttle at a speed of 2000 r/min for a period of 100 h with each of the fuel samples. The same lubricating oil, conventional SAE 40, was used in all the fuels. A multielement oil analyser (MOA) was used to measure the increase in wear of metals (Fe, Cu, Al, Pb) and the decrease in lubricating oil additives (Zn, Ca) in the lubricating oil used. An ISL automatic Houillon viscometer (ASTM D445) and potentiometric titration (ASTM D2896) were used to measure viscosity and total base number (TBN) respectively. The results show that the addition of anticorrosion additive with biofuel and lubricating oil improves the emission and engine wear characteristics; both the exhaust emission gases (NOx, CO and HCs) and the wear of metals (Fe, Cu, Al and Pd) decrease with the blended fuels in comparison with the base fuel OD. Detailed results, including engine brake power, are discussed.
Experimental investigation of the pressure drop in porous ceramic diesel particulate filters
Authors: Stratakis G A , Psarianos D L , Stamatelos A M
Published: November 2002

Understanding of the mechanisms that affect flow and pressure drop in porous ceramic diesel particulate filters is important in the design optimization of this class of diesel exhaust after- treatment systems. Furthermore, determination of the parameters involved in the calculation of pressure drop as a function of collected soot mass is important for successful filter loading and regeneration modelling. This paper presents the results of an experimental analysis of pressure drop as a function of the geometric and operating parameters of cordierite and SiC diesel filters. Single- cell filters from cordierite and silicon carbide were prepared to single out any effects from the complex flow processes that take place in a full-sized filter. The product of soot layer permeability and density was experimentally determined by employing a specially designed experimental apparatus. The calculation was supported by a simple computer calculation that is also presented in this paper. The distribution of soot loading inside the channels of a full-sized filter, in various loaded and partially regenerated conditions, was assessed by connecting the apparatus to discharge through selected channels of the filter. The results are shown to improve understanding of the effects of partial regeneration and fuel additive residuals on filter back pressure and flow and soot loading distribution.
Performance deterioration and durability issues while running a diesel engine with crude palm oil
Authors: Bari S , Yu C W , Lim T H
Published: November 2002

Short-term performance tests using crude palm oil (CPO) as fuel for a diesel engine showed CPO to be a suitable substitute, with a peak pressure about 5 per cent higher and an ignition delay about 3° shorter compared with diesel. Emissions of NO and CO were about 29 and 9 per cent higher respectively for CPO. However, prolonged use of CPO as fuel caused the engine performance to deteriorate. After 500 h cumulative running with CPO, the maximum power was reduced by about 20 per cent and the minimum brake specific fuel consumption (b.s.f.c.) was increased by about 26 per cent. Examination of the different parts after the engine was dismantled revealed heavy carbon deposits in the combustion chamber; traces of wear on the piston rings, the plunger and the delivery valve of the injection pump; slight scuffing of the cylinder liner; and uneven spray from the nozzles. The affected parts were installed in a new identical engine one by one to evaluate the performance of each respectively. Tests revealed that the main reason for engine performance deterioration was ‘valve sticking’, caused by carbon deposits on the valve seats and stems. This resulted in leakage during the compression and power strokes and a reduced effective compression ratio and subsequently affected the power and fuel economy. Valve sticking alone contributed about 18 and 23 per cent to the deterioration in maximum power and minimum b.s.f.c. respectively.
PRIMEGENS: robust and efficient
design of gene-specific probes for microarray analysis
Authors: Xu Dong , Li Guangshan , Wu Liyou , Zhou Jizhong , Xu Ying
Published: November 2002

Motivation: DNA microarray is a powerful high-throughput tool for studying gene function and regulatory networks. Due to the problem of potential cross hybridization, using full-length genes for microarray construction is not appropriate in some situations. A bioinformatic tool, PRIMEGENS, has recently been developed for the automatic design of PCR primers using DNA fragments that are specific to individual open reading frames (ORFs).

Results: PRIMEGENS first carries out a BLAST search for each target ORF against all other ORFs of the genome to quickly identify possible homologous sequences. Then it performs optimal sequence alignment between the target ORF and each of its homologous ORFs using dynamic programming. PRIMEGENS uses the sequence alignments to select gene- specific fragments, and then feeds the fragments to the Primer3 program to design primer pairs for PCR amplification. PRIMEGENS can be run from the command line on Unix/Linux platforms as a stand-alone package or it can be used from a Web interface. The program runs efficiently, and it takes a few seconds per sequence on a typical workstation. PCR primers specific to individual ORFs from Shewanella oneidensis MR-1 and Deinococcus radiodurans R1 have been designed. The PCR amplification results indicate that this method is very efficient and reliable for designing specific probes for microarray analysis.

Availability: The software is available at http://compbio.ornl.gov/structure/primegens/

Contact: xud@ornl.gov

* To whom correspondence should be addressed.
Ecological Predictions and Risk Assessment for Alien Fishes in North America
Authors: Kolar Cynthia S. , Lodge David M.
Published: November 2002

Methods of risk assessment for alien species, especially for nonagricultural systems, are largely qualitative. Using a generalizable risk assessment approach and statistical models of fish introductions into the Great Lakes, North America, we developed a quantitative approach to target prevention efforts on species most likely to cause damage. Models correctly categorized established, quickly spreading, and nuisance fishes with 87 to 94% accuracy. We then identified fishes that pose a high risk to the Great Lakes if introduced from unintentional (ballast water) or intentional pathways (sport, pet, bait, and aquaculture industries).
Conjunctival Biopsy of a Patient With Mpox
Authors: Tran Meagan , Gonzalez Valeria , Shah Ami , Patel Dharmendra , Shusko Alexander , McCullough Ann
Published: January 2024

This case report describes a conjunctival biopsy of a patient with mpox infection.
Epidermal Growth Factor Receptor Inhibitors for Lung Cancer and the Risk of Keratitis
Authors: Huang Pin-Chia , Lin Ching-Chieh , Dana Reza , Ma Kevin Sheng-Kai
Published: January 2024

Importance

Epidermal growth factor receptor inhibitors (EGFRis) have been reported to be associated with cutaneous and ocular side effects; however, there is limited evidence of an association between EGFRi treatment and keratitis.

Objective

To determine the association between EGFRi treatment and agents and the risk of new-onset keratitis among patients with lung cancer.

Design, Setting, and Participants

This US population–based cohort study examined TriNetX data of patients with lung cancer treated with or without EGFRis between May 1, 2003, and October 30, 2023.

Exposures

Treatment with EGFRis, including the first-generation agents gefitinib and erlotinib, the second-generation agent afatinib, and the third-generation agent osimertinib.

Main Outcomes and Measures

The risk of new-onset keratitis among patients with lung cancer receiving EGFRi treatment was determined using logistic and Cox proportional hazards regression.

Results

Among 1 388 108 patients with lung cancer, 22 225 received EGFRis (mean [SD] age, 69.7 [10.6] years; 62.8% females and 37.2% males). Patients treated with EGFRis had a higher risk of keratitis than nonexposed patients (hazard ratio [HR], 1.520; 95% CI, 1.339-1.725). Subtypes of EGFRi-associated keratitis included keratoconjunctivitis (HR, 1.367; 95% CI, 1.158-1.615), superficial keratitis (HR, 1.635; 95% CI, 1.306-2.047), and corneal ulcer (HR, 2.132; 95% CI, 1.515-3.002). Patients taking afatinib had a higher risk of keratitis (HR, 2.229; 95% CI, 1.480-3.356).

Conclusions and Relevance

These findings suggest that patients with lung cancer treated with EGFRis may have an increased risk of new-onset keratitis, especially with the second-generation EGFRi afatinib, supporting the need for prompt diagnosis and management of EGFRi-associated ocular issues to prevent serious complications or treatment disruptions.
Primary Classic Kaposi Sarcoma of the Parotid Gland in an HIV-Negative Patient
Authors: Batool Sana , Draper Elizabeth C. , Jo Vickie Y. , Sethi Rosh K. V.
Published: January 2024

This case report describes an HIV-negative man in his 60s of Mediterranean descent with hypertension, Hashimoto thyroiditis, nephrolithiasis, and gout who presented with a lump on the right side of his face and was subsequently diagnosed with Kaposi sarcoma.
Quantifying factors that explain the slopes of the temporal Taylor's law of Hokkaido vole populations
Authors: Saitoh Takashi , Cohen Joel E.
Published: January 2024

Taylor's law (TL) describes the relationship between the variance and mean of population density: log10(variance) ≈ log10(a) + b × log10(mean), a > 0. This study analyzed the temporal TL, for which mean and variance are calculated over time, separately for each population in a collection of populations, considering the effects of the parameters of the Gompertz model (a second‐order autoregressive time‐series model) and the skewness of the density frequency distribution. Time series of 162 populations of the gray‐sided vole in Hokkaido, Japan, spanning 23–31 years, satisfied the temporal TL: log10(variancej) ≈ 0.199 + 1.687 × log10(meanj). This model explained 62% of the variation of log10(variancej). An extended model with explanatory variables log10(meanj), the density‐dependent coefficient for 1‐year lag (α1,j), that for 2‐year lag (α2,j), the density‐independent variability (σj2), and the skewness (γj), explained 93.9% of the log10(variancej) variation. In the extended model, the coefficient of log10(meanj) was 1.949, close to the null value (b = 2) of the TL slope. The standardized partial regression coefficients indicated that density‐independent effects (σj2 and γj) dominated density‐dependent effects (α1,j and α2,j) apart from log10(meanj). The negative correlations observed between σj2 and log10(meanj), and between γj and log10(meanj), played an essential role in explaining the difference between the estimated slope of TL (b = 1.687) and the null slope (b = 2). The effects of those explanatory variables on log10(variancej) were interpreted based on the theory of a second‐order autoregressive time‐series model.
Off‐isocentric VMAT technique for breast cancer: Effective dose reduction to organs at risk and its applicability based on patient anatomy
Authors: Prokofev Igor , Salim Nidal
Published: January 2024

Purpose

This study aims to explore the off‐isocentric volumetric modulated arc therapy (offVMAT) technique for breast cancer and determine its applicability based on patient anatomical parameters.

Methods

We retrospectively analyzed 44 breast cancer patients with varied lymph node involvement using different arc designs. Off‐isocentric techniques were benchmarked against previously published arc techniques: classic arcs (clVMAT), tangential arcs (tVMAT), and split arcs (spVMAT). During optimization, target coverage was made for all plans as close as possible to the criteria D99% > 95% and Dmax < 110% of the prescribed dose. A novel patient categorization, based on anatomical parameters (auxiliary structures) rather than lymph node involvement, is introduced. This categorization considers the volume of ipsilateral organs at risk (OARs) adjacent to the target. A binary regression model was developed on these anatomical parameters. It predicts the likelihood of offVMAT (P[offVMAT]) achieving better criteria.

Results

Using the regression model, patients were divided into two groups: P(offVMAT) > 0.5 and P(offVMAT) < 0.5. For the P(offVMAT) > 0.5 group, most tVMAT plans are unable to achieve the clinical objectives. Comparing offVMAT with spVMAT, offVMAT exhibited better dose parameters for the heart (V20, V10, and D2 are 7.1, 2.4, and 1.5 times lower respectively), ipsilateral lung (V20, V10, V5 and the mean dose are 1.4, 1.3, 1.2, and 1.2 times lower respectively). The average doses to the contralateral side are consistent. In the P(offVMAT) < 0.5 group, the tVMAT technique showed increased doses at medium and high levels, yet reduced doses in contralateral OARs compared to spVMAT and offVMAT. spVMAT showed lower doses in the contralateral lung relative to the offVMAT technique, while clVMAT trailed in both groups. Validation of the model yielded a 90% accuracy rate.

Conclusions

The new off‐isocentric breast planning technique effectively reduces doses to ipsilateral OARs, maintaining acceptable contralateral mean doses. This technique has an advantage over other techniques for patients with intricate anatomies. It is evaluated using anatomical parameters, which are also used to build binary regression model, which shows the dependence of anatomical parameters on whether offVMAT is preferred for individual patients. Also, such anatomical parameters provide a more objective and precise comparison between different planning techniques.
Repeated iv anti‐CD20 treatment in multiple sclerosis: Long‐term effects on peripheral immune cell subsets
Authors: Feige Julia , Moser Tobias , Akgün Katja , Schwenker Kerstin , Hitzl Wolfgang , Haschke‐Becher Elisabeth , Ziemssen Tjalf , Sellner Johann
Published: January 2024

Objective

Repeated intravenous administration of anti‐CD20 depleting monoclonal antibodies 6 months apart is among the highly effective treatment options in multiple sclerosis (MS). Here, we aimed to investigate peripheral immune cell subset depletion kinetics following either rituximab (RTX) or ocrelizumab (OCR) infusions in people with MS (pwMS).

Methods

We studied pwMS treated de‐novo with either RTX (n = 7) or OCR (n = 8). The examinations were scheduled before the initiation of anti‐CD20 therapy and every 12 weeks for up to 15 months. Immunophenotyping of immune cell subsets in peripheral blood was performed by multiparametric fluorescence cytometry.

Results

A significant, persistent decrease of CD19+ B cells was observed already with the first anti‐CD20 infusion (p < 0.0001). A significant proportional reduction of memory B cells within the B‐cell pool was achieved only after two treatment cycles (p = 0.005). We observed a proportional increase of immature (p = 0.04) and naive B cells (p = 0.004), again only after the second treatment cycle. As for the peripheral T‐cell pool, we observed a continuous proportional increase of memory T helper (TH) cells/central memory TH cells (p = 0.02/p = 0.008), while the number of regulatory T cells (Treg) decreased (p = 0.007). The percentage of B‐cell dependent TH17.1 central memory cells dropped after the second treatment cycle (p = 0.02). No significant differences in the depletion kinetics between RTX and OCR were found.

Interpretation

Peripheral immune cell profiling revealed more differentiated insights into the prompt and delayed immunological effects of repeated intravenous anti‐CD20 treatment. The observation of proportional changes of some pathogenetically relevant immune cell subsets only after two infusion cycles deserves further attention.
Extracellular Vesicular Analysis of Glypican 1 mRNA and Protein for Pancreatic Cancer Diagnosis and Prognosis
Authors: Li Hong , Chiang Chi‐Ling , Kwak Kwang Joo , Wang Xinyu , Doddi Sital , Ramanathan Lakshmi V. , Cho Sun M. , Hou Ya‐Chin , Cheng Tai‐Shan , Mo Xiaokui , Chang Yueh‐Shih , Chang Hui‐Lan , Cheng Weiming , Tsai Wei‐Ni , Nguyen Luong T. H. , Pan Junjie , Ma Yifan , Rima Xilal Y. , Zhang Jingjing , Reategui Eduardo , Chu Yeh‐Shiu , Chang Peter Mu‐Hsin , Chang Pei‐Hung , Huang Chi‐Ying F. , Wang Cheng‐Hsu , Shan Yan‐Shen , Li Chung‐Pin , Fleisher Martin , Lee L. James
Published: January 2024

Detecting pancreatic duct adenocarcinoma (PDAC) in its early stages and predicting late‐stage patient prognosis undergoing chemotherapy is challenging. This work shows that the activation of specific oncogenes leads to elevated expression of mRNAs and their corresponding proteins in extracellular vesicles (EVs) circulating in blood. Utilizing an immune lipoplex nanoparticle (ILN) biochip assay, these findings demonstrate that glypican 1 (GPC1) mRNA expression in the exosomes‐rich (Exo) EV subpopulation and GPC1 membrane protein (mProtein) expression in the microvesicles‐rich (MV) EV subpopulation, particularly the tumor associated microvesicles (tMV), served as a viable biomarker for PDAC. A combined analysis effectively discriminated early‐stage PDAC patients from benign pancreatic diseases and healthy donors in sizable clinical from multiple hospitals. Furthermore, among late‐stage PDAC patients undergoing chemotherapy, lower GPC1 tMV‐mProtein and Exo‐mRNA expression before treatment correlated significantly with prolonged overall survival. These findings underscore the potential of vesicular GPC1 expression for early PDAC screenings and chemotherapy prognosis.
A Review on Magnetic Smart Skin as Human–Machine Interfaces
Authors: Zhang Junjie , Chen Guangyuan , Jin Zhenhu , Chen Jiamin
Published: January 2024

In recent years, there is a meteoric rise in the prevalence of electronic wearables, and flexible wearables have attracted tremendous attention in human–machine interfaces due to their high biocompatibility, functionality, conformability, and low‐cost. Flexible magnetic smart skin is part of this rapidly progressing field of flexible wearable electronics, which has paved the way for a new path for human perceptual development, as they may form a new perception, also known as magnetic sense, that is, the capacity to detect and interact with magnetic fields. In this review, the concept of the magnetic smart skin is defined: magnetoelastomers and flexible magnetic sensors. In magnetoelastomers, different sources of magnetic field, structures, and applications are summarized by recent and renowned research. In flexible magnetic sensors, different flexible substrates, sensor types, and applications are also summarized. This review further concludes by discussing the outlook and current challenges of magnetic smart skin in human–machine interfaces.
Multiple roles of agricultural cooperatives in improving farm technical efficiency: A case study of rural Gansu, China
Authors: Li Xinyi , Ito Junichi
Published: January 2024

The establishment of agricultural cooperatives is widely viewed as an institutional arrangement to remove constraints that prevent smallholders from accessing profitable business opportunities in agriculture. Agricultural cooperatives in China offer a wide range of services within the framework of contract farming and vertical integration. This study empirically examines the multiple roles of China's cooperatives in improving farm production efficiency and conserving the agricultural environment. Considering that agricultural cooperatives' services can be broadly divided into biological and machinery services, we specify a stochastic frontier production function in a special form, called the separated Cobb–Douglas. The empirical results present clear evidence that Chinese agricultural cooperatives play essential roles in increasing biochemical technical efficiency and protecting the agroecological environment. However, the involvement of cooperatives as vertical integrators is demonstrated to have a detrimental effect on biochemical technical efficiency. The pressing challenge for agricultural cooperative development in China is to accommodate the conflicting consequences that their entry into farming has on biochemical and machinery technical efficiencies. This has strong policy implications, although our study has certain limitations in terms of the narrow focus on a single specific region. [EconLit Citations: C26, Q12, Q13, Q15, Q18].
A Metal‐Free System for Conversion of Alcohols to Amides Using tert‐Butyl Nitrite
Authors: Indurthi Harish K. , Das Samarpita , Saha Pallavi , Sharma Deepak K.
Published: January 2024

A transition metal‐free cascade synthesis of amides from alcohols was developed. Various alcohols reacted with N‐hydroxyimides by tert‐butyl nitrite to generate N‐hydroxyimide esters. The resulting active esters were subsequently reacted with amines to generate amides in one pot. Further, we have illustrated the application of the developed protocol in synthesizing anti‐Alzheimer compounds. A detailed mechanistic exploration was also carried out.
Cobalt‐Catalyzed Enantioselective C−H Carbonylation towards Chiral Isoindolinones
Authors: Teng Ming‐Ya , Wu Yong‐Jie , Chen Jia‐Hao , Huang Fan‐Rui , Liu De‐Yang , Yao Qi‐Jun , Shi Bing‐Feng
Published: January 2024

Transition metal‐catalyzed enantioselective C−H carbonylation with carbon monoxide, an essential and easily available C1 feedstock, remains challenging. Here, we disclosed an unprecedented enantioselective C−H carbonylation catalyzed by inexpensive and readily available cobalt(II) salt. The reactions proceed efficiently through desymmetrization, kinetic resolution, and parallel kinetic resolution, affording a broad range of chiral isoindolinones in good yields with excellent enantioselectivities (up to 92 % yield and 99 % ee). The synthetic potential of this method was demonstrated by asymmetric synthesis of biological active compounds, such as (S)‐PD172938 and (S)‐Pazinaclone. The resulting chiral isoindolinones also serve as chiral ligands in cobalt‐catalyzed enantioselective C−H annulation with alkynes to construct phosphorus stereocenter.
pH‐Controlled Reversible Folding of Copolymers via Formation of β‐sheet Secondary Structures
Authors: Sbordone Federica , Micallef Aaron , Frisch Hendrik
Published: January 2024

Protein functions are enabled by their perfectly arranged 3D structure, which is the result of a hierarchical intramolecular folding process. Sequence‐defined polypeptide chains form locally ordered secondary structures (i.e., α‐helix and β‐sheet) through hydrogen bonding between the backbone amides, shaping the overall tertiary structure. To generate similarly complex macromolecular architectures based on synthetic materials, a plethora of strategies have been developed to induce and control the folding of synthetic polymers. However, the degree of complexity of the structure‐driving ensemble of interactions demonstrated by natural polymers is unreached, as synthesizing long sequence‐defined polymers with functional backbones remains a challenge. Herein, we report the synthesis of hybrid peptide‐N,N‐Dimethylacrylamide copolymers via radical Ring‐Opening Polymerization (rROP) of peptide containing macrocycles. The resulting synthetic polymers contain sequence‐defined regions of β‐sheet encoding amino acid sequences. Exploiting the pH responsiveness of the embedded sequences, protonation or deprotonation in water induces self‐assembly of the peptide strands at an intramacromolecular level, driving polymer chain folding via formation of β‐sheet secondary structures. We demonstrate that the folding behavior is sequence dependent and reversible.