scholarly journals A substantial improvement of the Stirling formula

2011 ◽  
Vol 24 (8) ◽  
pp. 1351-1354 ◽  
Author(s):  
Cristinel Mortici
Author(s):  
B. K. Kirchoff ◽  
L.F. Allard ◽  
W.C. Bigelow

In attempting to use the SEM to investigate the transition from the vegetative to the floral state in oat (Avena sativa L.) it was discovered that the procedures of fixation and critical point drying (CPD), and fresh tissue examination of the specimens gave unsatisfactory results. In most cases, by using these techniques, cells of the tissue were collapsed or otherwise visibly distorted. Figure 1 shows the results of fixation with 4.5% formaldehyde-gluteraldehyde followed by CPD. Almost all cellular detail has been obscured by the resulting shrinkage distortions. The larger cracks seen on the left of the picture may be due to dissection damage, rather than CPD. The results of observation of fresh tissue are seen in Fig. 2. Although there is a substantial improvement over CPD, some cell collapse still occurs.Due to these difficulties, it was decided to experiment with cold stage techniques. The specimens to be observed were dissected out and attached to the sample stub using a carbon based conductive paint in acetone.


2000 ◽  
Vol 20 (03) ◽  
pp. 136-142 ◽  
Author(s):  
D. L. Ornstein ◽  
L. R. Zacharski

SummaryIt is widely known that the systemic blood coagulation mechanism is often activated in malignancy, leading to an increased incidence of vascular thromboses in patients with cancer. It is not widely appreciated, however, that products of the coagulation mechanism may also support tumor growth and dissemination. Interest in this approach to cancer therapy has surged recently because of mounting evidence that the familiar anticoagulant drug, heparin, may impede tumor progression. Heparin has the capacity to modify angiogenesis, growth factor and protease activity, immune function, cell proliferation and gene expression in ways that may block malignant dissemination. Clinical trials in which heparin has been administered to a broad spectrum of patients to prevent or treat thrombosis have unexpectedly shown improvement in survival in the subset of patients with malignancy entered to these studies. Meta-analyses of clinical trials comparing unfractionated (UF) versus low molecular weight (LMW) heparin treating venous thromboembolism suggest that there may be substantial improvement in cancer outcome in patients with malignancy randomized to receive LMW heparin. These findings provide a rationale for definitive clinical trials of LMW heparin in cancer, and the results of several such studies that are currently underway are awaited with interest.


2002 ◽  
Vol 722 ◽  
Author(s):  
Ram W. Sabnis ◽  
Mary J. Spencer ◽  
Douglas J. Guerrero

AbstractNovel organic, polymeric materials and processes of depositing thin films on electronics substrates by chemical vapor deposition (CVD) have been developed and the lithographic behavior of photoresist coated over these CVD films at deep ultraviolet (DUV) wavelength has been evaluated. The specific monomers synthesized for DUV applications include [2.2](1,4)- naphthalenophane, [2.2](9,10)-anthracenophane and their derivatives which showed remarkable film uniformity on flat wafers and conformality over structured topography wafers, upon polymerization by CVD. The chemical, physical and optical properties of the deposited films have been characterized by measuring parameters such as thickness uniformity, solubility, conformality, adhesion to semiconductor substrates, ultraviolet-visible spectra, optical density, optical constants, defectivity, and resist compatibility. Scanning electron microscope (SEM) photos of cross-sectioned patterned wafers showed verticle profiles with no footing, standing waves or undercut. Resist profiles down to 0.10 νm dense lines and 0.09 νm isolated lines were achieved in initial tests. CVD coatings generated 96-100% conformal films, which is a substantial improvement over commercial spin-on polymeric systems. The light absorbing layers have high optical density at 248 nm and are therefore capable materials for DUV lithography applications. CVD is a potentially useful technology to extend lithography for sub-0.15 νm devices. These films have potential applications in microelectronics, optoelectronics and photonics.


Author(s):  
Jiyang Yu ◽  
Dan Huang ◽  
Siyang Zhao ◽  
Nan Pei ◽  
Huixia Cheng ◽  
...  

Author(s):  
Golokesh Santra ◽  
Nitai Sylvetsky ◽  
Gershom Martin

We present a family of minimally empirical double-hybrid DFT functionals parametrized against the very large and diverse GMTKN55 benchmark. The very recently proposed wB97M(2) empirical double hybrid (with 16 empirical parameters) has the lowest WTMAD2 (weighted mean absolute deviation over GMTKN55) ever reported at 2.19 kcal/mol. However, our xrevDSD-PBEP86-D4 functional reaches a statistically equivalent WTMAD2=2.22 kcal/mol, using just a handful of empirical parameters, and the xrevDOD-PBEP86-D4 functional reaches 2.25 kcal/mol with just opposite-spin MP2 correlation, making it amenable to reduced-scaling algorithms. In general, the D4 empirical dispersion correction is clearly superior to D3BJ. If one eschews dispersion corrections of any kind, noDispSD-SCAN offers a viable alternative. Parametrization over the entire GMTKN55 dataset yields substantial improvement over the small training set previously employed in the DSD papers.


2019 ◽  
Author(s):  
Golokesh Santra ◽  
Nitai Sylvetsky ◽  
Gershom Martin

We present a family of minimally empirical double-hybrid DFT functionals parametrized against the very large and diverse GMTKN55 benchmark. The very recently proposed wB97M(2) empirical double hybrid (with 16 empirical parameters) has the lowest WTMAD2 (weighted mean absolute deviation over GMTKN55) ever reported at 2.19 kcal/mol. However, our xrevDSD-PBEP86-D4 functional reaches a statistically equivalent WTMAD2=2.22 kcal/mol, using just a handful of empirical parameters, and the xrevDOD-PBEP86-D4 functional reaches 2.25 kcal/mol with just opposite-spin MP2 correlation, making it amenable to reduced-scaling algorithms. In general, the D4 empirical dispersion correction is clearly superior to D3BJ. If one eschews dispersion corrections of any kind, noDispSD-SCAN offers a viable alternative. Parametrization over the entire GMTKN55 dataset yields substantial improvement over the small training set previously employed in the DSD papers.


1987 ◽  
Vol 19 (12) ◽  
pp. 265-271
Author(s):  
P. R. Thomas ◽  
H. O. Phelps

The investigation was based on two facultative stabilization ponds initially designed to operate in parallel, and now receive wastewater in excess of their capacities from a fast expanding housing estate in the Caribbean Island of Trinidad. Because of the deterioration of the effluent quality relative to acceptable standards, an attempt was made to upgrade the ponds using water hyacinths at the early stages. However, from the results, it was clear that the introduction of water hyacinths in the test pond did not lead to any substantial improvement in the effluent because of the high loading on the pond. Therefore the ponds were modified to operate in series with surface aerators installed in the first pond. Initially, the effluent quality was monitored in terms of total suspended solids, volatile suspended solids, biochemical oxygen demand, faecal coliform bacteria, pH and dissolved oxygen with aeration in the first pond and no aquatic plants in the second pond. Although there was a significant improvement in the effluent quality, the values remained above the standards. As a result, water hyacinths were introduced in the second pond and the effluent quality monitored together with aeration in the first pond. The effluent quality improved with total suspended solids and biochemical oxygen demand values both as low as 10 mg/l in certain months, but additional treatment was needed to reduce faecal conforms.


2009 ◽  
Vol os16 (4) ◽  
pp. 137-142 ◽  
Author(s):  
Nick Kendall

This paper describes the innovative use of National Health Service (NHS) dental commissioning powers to develop specialist primary care based oral surgery services. The outcomes, after one full year of the scheme, have been substantial improvement in access and reduced waiting times for patients, further development of NHS primary care dental services through commissioning processes, increased use and engagement of oral surgery specialists outside of a hospital setting, and considerable ongoing savings to the NHS. Collaborative working between hospital consultants and managers, Primary Care Trust dental commissioners, general dental practice providers, specialist oral surgeons and a dental public health consultant has resulted in sustainable benefits to patients and the NHS within the World Class Commissioning framework.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vedran Stefanovic

Abstract Despite substantial improvement in reducing maternal mortality during the recent decades, we constantly face tragic fact that maternal mortality (especially preventable deaths) is still unacceptably too high, particularly in the developing countries, where 99% of all maternal deaths worldwide occur. Poverty, lack of proper statistics, gender inequality, beliefs and corruption-associated poor governmental policies are just few of the reasons why decline in maternal mortality has not been as sharp as it was wished and expected. Education has not yet been fully recognized as the way out of poverty, improvement of women’s role in the society and consequent better perinatal care and consequent lower maternal mortality. Education should be improved on all levels including girls, women and their partners, medical providers, religious and governmental authorities. Teaching the teachers should be also an essential part of global strategy to lower maternal mortality. This paper is mostly a commentary, not a systematic review nor a meta-analysis with the aim to rise attention (again) to the role of different aspects of education in lowering maternal mortality. The International Academy of Perinatal Medicine should play a crucial role in pushing the efforts on this issue as the influential instance that promotes reflection and dialog in perinatal medicine, especially in aspects such as bioethics, the appropriate use of technological advances, and the sociological and humanistic dimensions of this specific problem of huge magnitude. The five concrete steps to achieve these goals are listed and discussed.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Lisa Grossman Liu ◽  
Raymond H. Grossman ◽  
Elliot G. Mitchell ◽  
Chunhua Weng ◽  
Karthik Natarajan ◽  
...  

AbstractThe recognition, disambiguation, and expansion of medical abbreviations and acronyms is of upmost importance to prevent medically-dangerous misinterpretation in natural language processing. To support recognition, disambiguation, and expansion, we present the Medical Abbreviation and Acronym Meta-Inventory, a deep database of medical abbreviations. A systematic harmonization of eight source inventories across multiple healthcare specialties and settings identified 104,057 abbreviations with 170,426 corresponding senses. Automated cross-mapping of synonymous records using state-of-the-art machine learning reduced redundancy, which simplifies future application. Additional features include semi-automated quality control to remove errors. The Meta-Inventory demonstrated high completeness or coverage of abbreviations and senses in new clinical text, a substantial improvement over the next largest repository (6–14% increase in abbreviation coverage; 28–52% increase in sense coverage). To our knowledge, the Meta-Inventory is the most complete compilation of medical abbreviations and acronyms in American English to-date. The multiple sources and high coverage support application in varied specialties and settings. This allows for cross-institutional natural language processing, which previous inventories did not support. The Meta-Inventory is available at https://bit.ly/github-clinical-abbreviations.


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