bluuebunny/crossref_metadata_2025 huggingface dataset:
The high incidence of vascular thromboembolic events in patients with metastatic or unresectable urothelial cancer treated with platinum chemotherapy agents
Authors: Tully Christopher M. , Apolo Andrea B. , Zabor Emily C. , Regazzi Ashley M. , Ostrovnaya Irina , Furberg Helena F. , Rosenberg Jonathan E. , Bajorin Dean F.
Published: November 2015

BACKGROUND

The current study compared the incidence of vascular thromboembolic events (VTEs) in patients with metastatic or unresectable urothelial carcinoma (UC) who were treated with gemcitabine and carboplatin (GCb); gemcitabine, carboplatin, and bevacizumab (GCbBev); or gemcitabine and cisplatin (GCis).

METHODS

Patients with UC who were treated with GCbBev on protocol were analyzed prospectively and 2 contemporary control cohorts receiving GCb or GCis were evaluated retrospectively. VTE was defined as either venous or arterial (myocardial infarctions or cerebral vascular accidents) thrombosis. VTEs were considered to be related to treatment if they occurred during treatment or within 4 weeks of the completion of treatment. Associations with chemotherapy regimen were tested using either the Fisher exact test or Kruskal‐Wallis test. Clinical factors associated with VTEs were analyzed using conditional logistic regression stratified by treatment regimen.

RESULTS

Among 198 patients, VTEs occurred in 13 of 51 patients treated with GCbBev (26%), 22 of 92 patients treated with GCb (24%), and 8 of 55 patients treated with GCis (15%). Patient characteristics were significantly different between the treatment cohorts in terms of age, prior cystectomy, tumor location near pelvic vessels, Khorana risk group, and receipt of antiplatelet therapy. The incidence of VTE and type of VTE (arterial vs venous) did not differ by type of chemotherapy. Prior cystectomy was associated with an increased risk of VTE (odds ratio, 2.2; 95% confidence interval, 1.0‐4.9 [P = .047]).

CONCLUSIONS

The incidence of VTE in Cis‐treated patients was similar to prior reports. However, the VTE rate in Cb‐treated patients was > 20%, a figure not previously defined in patients with UC and higher than expected. This high incidence of both Cis‐related and Cb‐related VTEs warrants greater awareness by treating physicians and deserves further study. Cancer 2016;122:712–721. © 2015 American Cancer Society.
Cervical cancer prevention in Australia: Planning for the future
Authors: Saville A. Marion
Published: November 2015

The high rate of coverage that has been achieved to date by the Australian government's Human Papillomavirus (HPV) Vaccination Program has already led to profound reductions in the prevalence of biopsy‐confirmed, high‐grade abnormalities and of vaccine‐preventable HPV types in Australia. Declines in the prevalence of vaccine preventable HPV have occurred not only in vaccinated women but also in unvaccinated women, suggesting a herd‐immunity affect. These declines were anticipated on the basis of modelling and were the major drivers for the changes proposed to the Australian National Cervical Screening Program. The federal and state‐based Australian governments established a “Renewal Steering Committee,” which conducted a literature search and a review of the available evidence to assess its applicability and quality. Together with this information the committee also used modeling to determine the optimal screening pathway for cervical cancer screening and constructed a plan for implementing the changes that will be required to transition from the currently successful screening program to the renewed program. The committee recommended that Australia move to a screening program based on testing every 5 years using an HPV test with partial genotyping with reflex liquid‐based cytology (LBC) triage for HPV‐vaccinated and unvaccinated women ages 25 to 69 years, and an additional exit test for women up to age 74 years. Primary HPV testing and reflex LBC will be funded by government. Symptomatic women outside the screening program will also be able to access government funded testing. The new screening program, to be rolled out in 2017, will also provide a cost‐effective framework for an evaluation of the national HPV vaccination program, enabling ongoing monitoring of HPV genotypes and cervical lesions in screened women. Cancer Cytopathol 2016;124:235–40. © 2015 American Cancer Society.
Nickel Bicarbonate Revealed as a Basic Carbonate
Authors: Rincke Christine , Bette Sebastian , Dinnebier Robert E. , Voigt Wolfgang
Published: November 2015

A new basic nickel carbonate Ni12(CO3)8(OH)8·(x – 1)H2O or Ni12(CO3)8(OH)6O·xH2O (x = 6–8) was synthesized by two hydrothermal methods. The crystal structure was determined in the cubic space group P$\bar {4}$3m (215) with a = 8.3814(2) Å by laboratory high‐resolution X‐ray powder diffraction with the application of global optimization methods and Rietveld refinement. The crystal structure consists of edge‐linked [NiO6] octahedra and carbonate units that form cages. The interconnected cages form channels filled with disordered water molecules. This causes a zeolite‐like behavior of the water molecules, as shown by thermogravimetric analysis coupled with infrared spectroscopy (TG–IR) and in situ X‐ray powder diffraction experiments up to 300 °C. In addition, the title compound was characterized by elemental analysis, scanning electron microscopy, and Raman and UV/Vis spectroscopy. The title compound was proven to be a pure carbonate and not nickel hydrogen carbonate (PDF 15‐0782), as was assumed before.
A 8‐Hydroxyquinoline‐Cyclodextrin Conjugate as an Efficient Chelating Agent for Cobalt(II) and Nickel(II) in Neutral Aqueous Solution
Authors: Sgarlata Carmelo , Oliveri Valentina , Spencer John
Published: November 2015

Chelating agents offer a versatile and effective means of removing toxic metal ions from the human body. Mounting evidence suggests that exposure to nickel and cobalt causes a number of adverse nasal/pulmonary health effects, skin hazards and allergies. In this context, the development of chelators that are able to bind nickel and cobalt with high stability constants is clearly crucial. Herein, the interaction of cobalt(II) and nickel(II) with a 8‐hydroxyquinoline‐cyclodextrin conjugate was investigated in aqueous solution at neutral pH. This family of chelator under study is potentially relevant in the treatment of diseases related to metal dyshomeostasis. Stability constants for the cobalt(II) and nickel(II) complexes were determined by competition experiments. The data indicate the formation of stable complexes, which were characterized by spectroscopic techniques. The collected information may provide new insights and suggest further strategies for the development of hydroxyquinoline derivatives for the control of cobalt and nickel toxicity.
Use of Planar Chiral Ferrocenyl­phosphine‐Gold(I) Complexes in the Asymmetric Cycloisomerization of 3‐Hydroxylated 1,5‐Enynes
Authors: Wu Zhiyong , Retailleau Pascal , Gandon Vincent , Voituriez Arnaud , Marinetti Angela
Published: November 2015

Chiral monodentate phosphines based on ortho‐disubstituted ferrocene units have been prepared and used for the synthesis of gold(I) complexes. These complexes are highly active catalysts for the cycloisomerization of 3‐hydroxy‐1,5‐enynes into bicyclo[3.1.0]hexanones. Their high catalytic activity is ascribed to their structural analogy to the biaryl‐based Buchwald phosphines. This paper discloses the first enantioselective variant of these reactions based on gold catalysis (ee's up to 80 %).
Diabetes, metformin and incidence of and death from invasive cancer in postmenopausal women: Results from the women's health initiative
Authors: Gong Zhihong , Aragaki Aaron K. , Chlebowski Rowan T. , Manson JoAnn E. , Rohan Thomas E. , Chen Chu , Vitolins Mara Z. , Tinker Lesley F. , LeBlanc Erin S. , Kuller Lewis H. , Hou Lifang , LaMonte Michael J. , Luo Juhua , Wactawski‐Wende Jean
Published: November 2015

Findings from studies of metformin use with risk of cancer incidence and outcome provide mixed results; with few studies examined associations by recency of diabetes diagnosis or duration of medication use. Thus, in the Women's Health Initiative, we examined these associations and further explored whether associations differ by recency of diabetes and duration of metformin use. Cox regression models were used to estimate hazard ratios (HR) and their 95% confidence intervals. Diabetes was associated with higher risk of total invasive cancer (HR, 1.13; p < 0.001) and of several site‐specific cancers (HR, 1.2–1.4, and up to over twofold). Diabetes was also associated with higher risk of death from cancer (HR, 1.46; p < 0.001). There was no overall difference in cancer incidence by diabetes therapy (p = 0.66). However, there was a lower risk of death from cancer for metformin users, compared to users of other medications, relative to women without diabetes, overall (HRs, 1.08 vs. 1.45; p = 0.007) and for breast cancer (HRs, 0.50 vs. 1.29; p = 0.05). Results also suggested that lower cancer risk associated with metformin may be evident only for a longer duration of use in certain cancer sites or subgroup populations. We provide further evidence that postmenopausal women with diabetes are at higher risk of invasive cancer and cancer death. Metformin users, particularly long‐term users, may be at lower risk of developing certain cancers and dying from cancer, compared to users of other anti‐diabetes medications. Future studies are needed to determine the long‐term effect of metformin in cancer risk and survival from cancer.
Physical‐Organic Chemistry: A Swiss Army Knife
Authors: Whitesides George M.
Published: November 2015

“Physical‐organic chemistry” is the name given to a subfield of chemistry that applies physical‐chemical techniques to problems in organic chemistry (especially problems involving reaction mechanisms). “Physical‐organic” is, however, also a short‐hand term that describes a strategy for exploratory experimental research in a wide range of fields (organic, organometallic, and biological chemistry; surface and materials science; catalysis; and others) in which the key element is the correlation of systematic changes in molecular structure with changes in properties and functions of interest (reactivity, mechanism, physical or biological characteristics). This perspective gives a personal view of the historical development, and of possible future applications, of the physical‐organic strategy.
The Nitric Oxide Prodrug JS‐K Induces Ca2+‐Mediated Apoptosis in Human Hepatocellular Carcinoma HepG2 Cells
Authors: Liu Ling , Wang Dongmei , Wang Jiangang , Wang Shuying
Published: November 2015

Hepatocellular carcinoma is one of the most common and deadly forms of human malignancies. JS‐K, O2‐(2, 4‐dinitrophenyl) 1‐ [(4‐ethoxycarbonyl) piperazin‐1‐yl] diazen‐1‐ium‐1, 2‐diolate, has the ability to induce apoptosis of tumor cell lines. In the present study, JS‐K inhibited the proliferation of HepG2 cells in a time‐ and concentration‐dependent manner and significantly induced apoptosis. JS‐K enhanced the ratio of Bax‐to‐Bcl‐2, released of cytochrome c (Cyt c) from mitochondria and the activated caspase‐9/3. JS‐K caused an increasing cytosolic Ca2+ and the loss of mitochondrial membrane potential. Carboxy‐PTIO (a NO scavenger) and BAPTA‐AM (an intracellular Ca2+ chelator) significantly blocked an increasing cytosolic Ca2+ in JS‐K‐induced HepG2 cells apoptosis, especially Carboxy‐PTIO. Meanwhile, Carboxy‐PTIO and BAPTA‐AM treatment both attenuate JS‐K‐induced apoptosis through upregulation of Bcl‐2, downregulation of Bax, reduction of Cyt c release from mitochondria to cytoplasm and inactivation of caspase‐9/3. In summary, JS‐K induced HepG2 cells apoptosis via Ca2+/caspase‐3‐mediated mitochondrial pathway.
Polydatin Induces Apoptosis and Inhibits Growth of Acute Monocytic Leukemia Cells
Authors: Wang Chunmei , Luo Yuan , Lu Jie , Wang Yingchao , Sheng Guangyao
Published: November 2015

Polydatin (PD), a component isolated from Polygonum cuspidatum, has various activities such as inhibiting platelet aggregation, lowering level of blood lipid, reducing lipid peroxidation, and so on. However, the antitumor activity of PD has been poorly reported. In the present study, effect of PD on cell proliferation was evaluated by Cell Counting Kit‐8, and cell cycle and apoptosis were investigated by flow cytometry. Meanwhile, the protein expression level of Bc1‐2, Bax, cyclin A, cyclin B, and cyclin D1, which associated with apoptosis and cell cycle were analyzed by Western blotting. Results show that PD could effectively inhibit the growth, arrest cells in S phase, and induce apoptosis of acute monocytic leukemia cell line THP‐1; meanwhile, expression of cyclin D1 and Bc1‐2 decreased significantly, and expression of Bax and cyclin A increased notably. All results suggest that PD maybe a potential therapeutic strategy for acute monocytic leukemia.
Spatiotemporal characteristics of hourly precipitation over central eastern China during the warm season of 1982–2012
Authors: Li Deshuai , Sun Jianhua , Fu Shenming , Wei Jie , Wang Shigong , Tian Fuyou
Published: November 2015

An intensive observational hourly precipitation data set from the China Meteorological Administration was utilized to investigate the changes in precipitation amount, frequency, intensity and duration over central eastern China during the warm season from 1982 to 2012. Ten intensity categories were used to reveal the contributions of precipitation frequency and intensity to the variation of rainfall amount. Moreover, the trends of frequency were also evaluated by comparing the respective contributions of the number and the duration of precipitation events. The main results are as follows: (1) The precipitation amount and intensity both decreased from southeast to northwest China, with two areas of high precipitation frequency located in southwestern and southeastern China. A region of high precipitation duration was found in central China and two lower duration regions were found in southern and northern China. (2) Generally, the extreme heavy rainfall showed a significant increasing trend while the light rainfall showed a significant decreasing trend over central eastern China. Nevertheless, the spatial unevenness was detected and in south and southeast China, significant increasing trends were found, whereas in northeast China and the Sichuan Basin, precipitation amounts showed a declining trend in each precipitation intensity category. (3) The trends of precipitation amount were mainly caused by the variations of precipitation frequency, which had a contribution rate of greater than 95%; however, for the heavy rainfall category, intensity changes were also very important. (4) Increased precipitation frequency was largely caused by the prolonged duration of rainfall events, whereas the decreased frequency was mainly due to the reduction in the number of rainfall events.
Evolution of Chemical Characteristics of Technosols in an Afforested Coal Mine Dump over a 20‐year Period
Authors: Rivas‐Pérez Ivana M. , Fernández‐Sanjurjo María J. , Núñez‐Delgado Avelino , Monterroso Carmen , Macías Felipe , Álvarez‐Rodríguez Esperanza
Published: November 2015

Coal mining in areas containing pyritic materials frequently leads to a remarkable impact on the environment because of sulphide oxidation. We studied the evolution of chemical characteristics of Technosols derived from sterile materials, in a lignite mine located in As Pontes (northwest Spain), over a 20‐year period. Three plots, which had different management practices, were selected. The mine spoil was deposited randomly in two of the plots (CSP with low S concentration and CSA with high S concentration), while it was selectively managed in the other one (P206). Twenty years after the first sampling, CSA continued to show the highest acidity (pHwater 3∙7–3∙9), whereas the lowest acidity was that of P206 (pHwater 5∙0). Regarding the surface layer, C increased 1∙1% in P206, 0∙3% in CSP and 0∙2% in CSA. Nitrogen increased 1% in P206. The C/N ratio increased in all plots. Phosphorus, Ca, Mg, K and effective cation exchange capacity decreased in 2002 and experienced a slight increase in 2012. Exchangeable Al and Al saturation increased in CSP and P206 and decreased in CSA. Electric conductivity levels of Ca, Mg, Na, Al and SO42− concentrations decreased in the soil solution in all plots during the 20‐year period. Twenty years after the first monitoring, the plots that were built based on selective management of the mine spoil showed lower acidity and acidity‐derived consequences. These facts confirm the necessity of an appropriate selection of sterile materials, avoiding the placement of pyrite‐rich spoils on the surface or near‐surface zones, which is essential to facilitate proper restoration of this kind of dumping areas. Copyright © 2015 John Wiley & Sons, Ltd.
Anisotropic Lithium Ion Conductivity in Single‐Ion Diblock Copolymer Electrolyte Thin Films
Authors: Aissou Karim , Mumtaz Muhammad , Usluer Özlem , Pécastaings Gilles , Portale Giuseppe , Fleury Guillaume , Cloutet Eric , Hadziioannou Georges
Published: November 2015

Well‐defined single‐ion diblock copolymers consisting of a Li‐ion conductive poly(styrenesulfonyllithium(trifluoromethylsulfonyl)imide) (PSLiTFSI) block associated with a glassy polystyrene (PS) block have been synthesized via reversible addition fragmentation chain transfer polymerization. Conductivity anisotropy ratio up to 1000 has been achieved from PS‐b‐PSLiTFSI thin films by comparing Li‐ion conductivities of out‐of‐plane (aligned) and in‐plane (antialigned) cylinder morphologies at 40 °C. Blending of PS‐b‐PSLiTFSI thin films with poly(ethylene oxide) homopolymer (hPEO) enables a substantial improvement of Li‐ion transport within aligned cylindrical domains, since hPEO, preferentially located in PSLiTFSI domains, is an excellent lithium‐solvating material. Results are also compared with unblended and blended PSLiTFSI homopolymer (hPSLiTFSI) homologues, which reveals that ionic conductivity is improved when thin films are nanostructured.

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Tissue inhibitor of metalloproteinases‐4 (TIMP‐4) regulates stemness in cervical cancer cells
Authors: Lizarraga Floria , Espinosa Magali , Ceballos‐Cancino Gisela , Vazquez‐Santillan Karla , Bahena‐Ocampo Ivan , Schwarz‐Cruz y Celis Angela , Vega‐Gordillo Montserrat , Garcia Lopez Patricia , Maldonado Vilma , Melendez‐Zajgla Jorge
Published: November 2015

Tissue inhibitor of metalloproteinase‐4 (TIMP‐4) belongs to a family of extracellular matrix (ECM) metalloproteinases inhibitors that are overexpressed in several cancers. However, the role of TIMP‐4 during carcinogenesis is poorly understood. To evaluate TIMP‐4 functions in carcinogenesis, stably transfected cells overexpressing this tissue inhibitor were used. Xenograft tumor growth, stem cell enrichment, colony formation, and gene regulation were investigated. Microarrays and in silico analysis were carried out to elucidate TIMP‐4 molecular mechanisms. In the present report, we show that in nude mice, cervical cancer cells that overexpress TIMP‐4 formed tumors faster than control cell‐derived tumors. Furthermore, in vivo limiting dilution assays showed that fewer TIMP‐4 overexpressing cells are needed for tumor formation. In vitro analyses demonstrated that TIMP‐4 overexpression or exposure to human recombinant TIMP‐4 (hrTIMP4) caused an enrichment of the tumor progenitor cell (TPC) population. Accordingly, genome‐wide expression and signaling pathway analyses showed that hrTIMP‐4 modulated cell survival, cell proliferation, inflammation, and epithelial‐mesenchymal transition (EMT) signaling networks. Notably, NFκB signaling pathway appeared to be globally activated upon hrTIMP‐4 treatment. Overall, this report provides the first example that TIMP‐4 regulates carcinogenesis through enriching the TPC population in cervical cancer cells. Understanding TIMP‐4 effects on tumorigenesis may provide clues for future therapies design. © 2015 Wiley Periodicals, Inc.
Anti‐inflammatory and anti‐chemotactic effects of dietary flaxseed oil on CD8+ T cell/adipocyte‐mediated cross‐talk
Authors: Monk Jennifer M. , Liddle Danyelle M. , Brown Morgan J. , Zarepoor Leila , De Boer Anna A. , Ma David W. L. , Power Krista A. , Robinson Lindsay E.
Published: November 2015

Scope

CD8+ T cell/adipocyte paracrine interactions represent a critical step in the development of the obese inflammatory phenotype that is disrupted by long‐chain n‐3 PUFA. Our objective was to determine the effect of flaxseed‐derived n‐3 PUFA (α‐linolenic acid) on these paracrine interactions.

Methods and results

C57BL/6 mice were fed 3.5% flaxseed oil (FX) + 3.5% corn oil diet w/w or an isocaloric 7% corn oil w/w control diet (CON) for 3 wk. 3T3‐L1 adipocytes and purified primary splenic CD8+ T cells were cocultured at an obese cellular ratio (10% CD8+ T cells) and LPS‐stimulated (10 ng/mL mimicking obese circulating endotoxin levels) for 24 h. FX cocultures reduced (i) secreted IL‐6, tumor necrosis factor α (TNF‐α), macrophage chemoattractant protein 1 (MCP‐1), macrophage inflammatory protein 1α (MIP‐1α), and RANTES (regulated on activation, normal T cell expressed and secreted) levels; (ii) activation of inflammatory transcription factors NFκB (nuclear factor kappa‐light‐chain‐enhancer of activated B cell) p65 and signal transducer and activator of transcription‐3 (STAT3); and (iii) RAW264.7 macrophage chemotaxis versus CON (p ≤ 0.05). Coculture of pre‐inflamed adipocytes (10 ng/mL LPS, 24 h prior to CD8+ T‐cell addition) resulted in reduced secretion of IL‐6, IL‐1β, MCP‐1, MCP‐3, MIP‐1β, and RANTES in FX cocultures versus CON (p ≤ 0.05).

Conclusion

FX exerts an anti‐chemotactic and anti‐inflammatory effect on CD8+ T cell/adipocyte paracrine interactions (cross‐talk), which has the potential to mitigate macrophage chemotaxis which drives components of the obese phenotype.
Intrauterine fetal demise after prenatal diagnosis of congenital heart disease: assessment of risk
Authors: Divanovic Allison , Bowers Katharine , Michelfelder Erik , Jaekle Ronald , Newman Tondra , Marcotte Michael , Habli Mounira , Cnota James F.
Published: November 2015

Objectives

Elective deliveries in fetal congenital heart disease (CHD) attempt to balance fetal and neonatal risk with the goal of optimizing overall outcome. However, the magnitude of the risk for intrauterine fetal demise (IUFD) is unclear. This study aimed to (1) determine the rate of IUFD and (2) identify fetal risk factors associated with IUFD.

Methods

Retrospective review of pregnancies complicated by CHD between 1998 and 2010. Data were collected regarding pregnancy outcome, extracardiac anomalies (ECA), genetic and cardiac diagnoses, severity of valve regurgitation, gestational age at birth and birth weight. Fisher's exact test and odds ratios were used to compare outcomes between groups.

Results

A total of 501 pregnancies analyzed resulted in 445 live births, 22 IUFD, 16 terminations and 18 unknown outcomes. Amongst IUFD, 27% had a genetic diagnosis, 50% had an ECA and 27% had severe valve regurgitation. IUFD odds increased threefold with ECA and sevenfold with severe valve regurgitation. IUFD occurred in 1.2% without risk factors.

Conclusions

IUFD in fetuses with CHD is associated with ECA, genetic syndromes and severe valve regurgitation. In absence of these fetal characteristics, the occurrence of IUFD is low, although it remains higher than in fetuses without CHD. © 2015 John Wiley & Sons, Ltd.
Spectral library searching in proteomics
Authors: Griss Johannes
Published: November 2015

Spectral library searching has become a mature method to identify tandem mass spectra in proteomics data analysis. This review provides a comprehensive overview of available spectral library search engines and highlights their distinct features. Additionally, resources providing spectral libraries are summarized and tools presented that extend experimental spectral libraries by simulating spectra. Finally, spectrum clustering algorithms are discussed that utilize the same spectrum‐to‐spectrum matching algorithms as spectral library search engines and allow novel methods to analyse proteomics data.
Half‐Heusler materials as model systems for phase‐separated thermoelectrics
Authors: Fecher Gerhard H. , Rausch Elisabeth , Balke Benjamin , Weidenkaff Anke , Felser Claudia
Published: November 2015

Semiconducting half‐Heusler compounds based on NiSn and CoSb have attracted attention because of their good performance as thermoelectric materials. Nanostructuring of the materials was experimentally established through phase separation inalloys when mixing different transition metals (T,,) or main group elements (M,). The electric transport properties of such alloys depend not only on their micro‐ or nanostructure but also on the atomic‐scale electronic structure. In the present work, the influence of the band structure and density of states on the electronic transport and thermoelectric properties is investigated in detail for the constituents of phase‐separated half‐Heusler alloys. The electronic structure is calculated using different theoretical schemes for ordered and disordered materials. It is found that chemical disorder scattering influences the electronic transport properties in all substituted materials. Substitution in NiSn‐based compounds leads to high performance n‐type materials but only moderate p‐type thermoelectric properties. The latter is caused by the influence of the valence band on the conductivity. For CoSb‐based compounds, it is found that Sb substitution with Sn keeps the bands close to the Fermi energy intact. The resulting substituted alloys are excellent p‐type materials because of the characteristic valence band structure in thedirection.

The figure shows thefcccrystal structure () of the half‐Heusler compounds (prototype: MgAgAs,,, 216).
Some Results of Electron Content Measurements at Delhi From Faraday Fading of S‐66 Transmissions
Authors: Tyagi Tuhi Ram , Somayajulu Y. V.
Published: November 2015

This paper contams the results of analysis of the total electron content (Is) measurements made from the recordings of Faraday rotation at Delhi of the 20‐ and 40‐Mc/s transmissions of the satellite Explorer 22 (S‐<16) for the period October 1964 through June 1965, the period of low solar activity. The results show that the diurnal maximum is reached around 1300‐1400 1ST, while at night the electron content falls to low values, decreasing slowly with time until 0600 when it starts to increase. The variations in Isclosely follow the f0F2, variations. The ratio I, smax/Isminincreases from 7 for OctoberDecember 1964 through 10 for January‐March 1965 to about 25 for April‐June 1965. It is interesting to note that electron content values are more or less independent of solar activity until the 10‐cm solar flux exceeds about 80 units. Above 80 units, there is a positive correlation. The study of dependence ofIson magnetic activity shows that there is posiiive correlation during daytime, while nighttime values do not show any dependence on magnetic activity. In addition, the electron content seems to have a correlation with solar zenith angle. General features of the thickness parameter T and the ratio of total to subpeak electron contemIs//b are also given. The variations ofT are correlated with both solar flux anJ hm‐F~ variations. Preliminary examination of occurrence of scintillations is also given.
On the Topside Ionosphere Over the American Continents
Authors: Chan K. L.
Published: November 2015

Preliminary results of an extensive investigation of the topside ionosphere over the North and South American continents are presented. The required data are obtained through the reduction and analysis of a large number of Alouette I topside ionograms. Illustrative examples of typical latitudinal variations (from 80° N to 80° S geographic latitudes or 90° N to 60° S dip latitudes) of electron density (N) and corresponding scale height (Hu) are presented. The characteristic features of equatorial, midlatitude and polar ionospheres are described. Assuming the topside ionosphere is in a state of diffusive equilibrium above 500 km, the scale height of electron distribution along magnetic field lines (Hs) is calculated. The physical significance and interpretation of the computed scale height, (Hs), curves are discussed.
Brief Review of Scintillation Studies
Authors: Briggs B. H.
Published: November 2015

A brief review is given of certain selected aspects of radio star and satellite scintillations. The topics discussed include the theory of wave propagation through random media, the bandwidth of scintillations, secondary effects which may reduce scintillations, and interplanetary scintillations. The review. ends with a discussion of some outstanding problems in this field.
Parameters of a Cloud‐Like Distribution of Electrons in the Ionosphere
Authors: Hughes Leroy R.
Published: November 2015

Wide bandwidth differential phase measurements have been taken on the 162 and 324 Mc/s emissions of Anna lB and 63038c satellites from Point Buchan, Calif. and College, Alaska. The measurements are analyzed to determine parameters describing fine scale electron distribution in contrast to smooth ionosphere parameters.

Electron content variations show a cloud‐like structure with apparent scale sizes less than 20 m in both day and night ionospheres.
Calculations of Apparent Sky Temperature at Millimeter Wavelengths
Authors: Falcone Vincent J.
Published: November 2015

Apparent sky tempetatures measured at 15, 17, and 35 Gc/s over a period of a year are compared with values calculated from the nidiative transfer equation. Temperature, pressure, and relative humidity profiles, which are necessary to solve the radiative equation, are obtained from radiosonde data which are taken simultaneousJy with radiometric measurements. It is found that apparent sky temperatures calculated using the presently accepted line breadth constant for oxygen are not in good agreement with measured values. It is shown that by increasing the oxygen line breadth constant, calculated values within experimental error of measured apparent sky temperatures are obtained.
Design of a Satellite‐to‐Satellite Communications Experiment To Explore HF/VHF Guided Propagation in the Lower Ionosphere
Authors: Barker James I. , Grossi Mario D.
Published: November 2015

The design of an experiment to provide conclusive proof of the existence of HF/VHF whispering gallery propagation in the ionosphere below F2Hmax (and to explore its characteristics) has recently been completed and the necessary instrumentation developed and built.

The design has been performed on the basis of the results of the simulation of the phenomenon in a digital computer which has integrated in a self‐consistent model the fragmentary, incomplete knowledge of the phenomenon available to date.

A satellite‐to‐satellite configuration has be~n chosen, as suitable both to prove unambiguously the existence of whispering‐gallery propagation in the lower ionosphere, and for gathering information basic to the evaluation of the practical usefulnes~ of the guided paths for communications, and to their channel characterization.
Rotating Interferometer and Its Use in Measuring the Spread and Coherence Ratio of a Scattered Radio Wave
Authors: Whale H. A. , Bannister R. W.
Published: November 2015

Developments in the use of a rotating interferometer for measurements of bearing and elevation angles, for determination of the vertical and horizontal spreads in the power in the incoming cone of rays, and for determination of the correlation between these, are described. It is shown that, using an auxiliary fixed remote antenna, a very simple method of measuring the coherence ratio, i.e., deriving the value of the specular component, is possible.
Microwave Scattering From an Underdense Turbulent Plasma
Authors: Guthart H. , Weissman D. E. , Morita T.
Published: November 2015

The bistatic radar cross section of an underdense, inhomogeneous turbulent plasma was measured at X‐band and the results were compared with a theoretical model. The turbulent plasma was formed by seeding a premixed ethylene‐oxygen flame in a combustion chamber and exhausting it through an expansion nozzle into a low‐pressure vessel. Electrostatic probes, biased for ion collection, were used to map the variation of the mean and rms electron density throughout the turbulent regions and to measure the correlation coefficient of the plasma fluctuations. A theoretical scattering model was constructed using the Born approximation and the results of the diagnostic measurement program. Good agreement between theory and experiment has been obtained for the dependence of cross section on bistatic angle and for the spectrum of fluctuations of the scattered microwave signal. The predicted cross section underestimates the measured cross section by 6 to 11 dB when the measured cross sections are in the range from 10−8 to 10−5 m2. The measured cross section was observed to have a square‐law dependence on electron density in agreement with the Born model for densities up to one percent of the critical electron density. For densities beyond this, the Born approximation breaks down and the cross‐section dependence becomes linear.
Current in a Scattering Antenna Embedded in a Dissipative Half Space
Authors: Tuan H. S. , King Ronold W. P.
Published: November 2015

The current distribution on a half‐wave dipole antenna embedded in a conducting half space is investigated. The dipole antenna is parallel to the plane of the interface between the two media. It is illuminated by a diffracted inhomogeneous plane wave with perpendicular magnetic field vector. The current distribution is found mainly cosinusoidal with a shifted cosine correction term. A numercial analysis is given for the case where the dissipative medium has average earth constants. variations of the current due to different angles of incidence are also investigated.
U.S.A. National Assembly, Committee Report, Fifteenth URSI General Munich, September 1966: Commission 6, Radio Waves and Transmission OF Information; Progress. in Radio Waves and Transmission of
Authors: Darlington S. , Felsen L. B. , Siegel K. M. , Deschamps G. , Hansen R. C. , Ishimaru A. , Keller J. B. , King R. W. P. , Marcuvitz N. , Senior T. B. A. , Sletten C. J. , Tai C. T. , Twersky V. , Zucker F. J.
Published: November 2015

Many important papers have appeared; only a few can be given here. In cylindrical antenna theory, accurate current and field distributions were found for isolated [King and Wu, 1965] and coupled [King and Sandler, 1964] elements. A fine summary of broadband antennas by Jordan was referenced in recent studies of log‐spiral antennas [Dyson, 1965]. New structures included the wire‐grid HF Luneburg lens [Sharp, 1965] and double‐helix antennas [Ehrenspeck, 1965]. Advances in large quasi‐optical antennas included an analysis of focal fields and line source feeds for spherical reflectors [Schell, 1963]; analysis of reflector‐subreflector systems such as Cassegrain and Gregorian types [Morgan, 1964]; and a book treating aperture antennas and including many references [Hansen, 1964]. Progress in optical scanning systems included geodesic Luneburg lenses [Ruddock, Ryan, and Walter, 1964], bootlace lenses [Kales and Brown 1965], and parallel‐plate scanners [Rotman and Turner, 1963]. Electronic scanning of phased arrays received major attention. Mutual impedance changes With scan angles were analyzed by the impedance crater concept [Rhodes, 1964]; also techniques for compensating for these changes were developed [Hannan, Lerner, and Knittel, 1965). Important progress has been made in digital phase shifters. The diode type [White, 1965] has recently been supplemented by latching types employing ferrite cores [Whicker and Jones, 1965]. Adaptive array systems were covered in a special issue [IEEE, 1964]; of particular interest are the Gruenberg paper on retrodirective systems and the Skolnik and King paper on selfsteering arrays. The annular slot array has been developed for monopulse [Kelly and Goebels, 1964]. Nonuniformly spaced array sidelobes have been bounded by a probabilistic approach [Lo, 1964]. Finally, the important but long unsolved problem of an optimum directivity source with supergain ratio constraint was formally solved [Rhodes, 1963].
U.S.A. National Committee Report, Fifteenth URSI Assembly, Munich, September 1966: Radio Electronics; Progress in Radio Electronics
Authors: Heffner Hubert , Gould Roy W. , Siegman A. E. , Whinnery J. R.
Published: November 2015

The generation of new laser devices, techniques, ideas, and applications continued at an unslowing pace during 1963–1966. While no large‐scale or commercially important laser applications have yet emerged, lasers have found innumerable and often irreplaceable applications both in science and in technology. Increasing numbers of useful commercial applications are slowly beginning to emerge at the end of the period.
Effect of Meteoric Dust on the Effective Recombination Coefficient in the Lower Ionosphere
Authors: Parthasarathy R. , Rai D. B.
Published: November 2015

The effect of meteoric dust particles on the steady‐state distribution of electrons and ions in the lower ionosphere (50‐90 km) has been investigated. A formal expression for the effective recombination coefficient has also been derived, containing the terms for the rates of capture of electrons and positive and negative ions by the dust. These capture rates are derived by an extension of Natanson's theory of aerosol charging by the capture of ions. The altitude dependence of these coefficients is mainly determined by the altitude distribution of the dust concentration. It is found that only particles with radii larger than about a tenth of a micron play a significant role.

The numerical values of the effective recombination coefficient for several altitudes in the D region have been compared with the values empirically determined by us from multiple‐frequency radiowave absorption data in the auroral zone, and found to be in satisfactory argeement. It is also shown that the role of dust concentration in the D region is of major significance when the ionization density is weak to moderate. For a strongly ionized D region, the role is significant only if the dust concentration is higher than is currently believed probable.
Change Polarization on Reflection From a Tilted Plane
Authors: Mitzner K. M.
Published: November 2015

Beckmann's study of the effect on polarization of reflection from a tilted plane is modified and extended to the case of partial polarization. The approach used is simpler than Beckmann's and exhibits the symmetry of the results. Some errors in Beckmann's work are corrected.
The Structure of the Sporadic E Layer Detected from VHF Ionospheric Propagation
Authors: Kazuhiko Tao
Published: November 2015

From the statistical result of sporadic E propagation carried out on the frequency of 50 Mc/s, there is, in general, a fairly good correlation between the received field intensity and the critical frequency of the sporadic E layer measured at apex. This relation, however, is not always vahd for each case; i.e., the transmission loss of the received signal depends not only on the value of f0Es;, but also on the layer thickness and the distribution of electron density within the layer. The distribution of electron density in the sporadic E layer is deduced from both data of transmisssion loss and critical frequency at apex, if the sporadic E layer is assumed to be an extremely thm ionized layer.
Sporadic E and Ionospheric Currents
Authors: Matsushita S.
Published: November 2015

The present status of our knowledge concerning sporadic E in middle latitudes, wind‐shear theory of the formation of sporadic E, and wind systems in the ionospheric E region is briefly summarized. Then, possible correlations between sporadic E in middle latitudes and ionospheric current and wind systems estimated from geomagnetic variations are discussed from the point of view of the wind‐shear theory.
Some Problems Associated With Midlatitude Sporadic E
Authors: Cole Keith D. , Norton Richard B.
Published: November 2015

There are many problems yet to be resolved in this field.

If it is assumed that the major ions in sporadic E are NO+ and O+, then ionospheric studies and laboratory measurements suggest an appropriate value of α (the recombination coefficient) to be of order 10−7 cm3 sec−1 at room temperatures. This conflicts with the highest value of α tolerable to wind‐shear theory of about 3 × 10−8 cm3 sec−1. High electron temperatures in sporadic E clouds may reduce this discrepancy if a decreases with increase of temperature. In its present stage of development the windshear theory does not account for the high electron temperatures sometimes observed in association with sporadic E, nor does it account for the magnetic variation observed in association with sporadic E clouds.

The possibility of an airglow component caused by recombination in sporadic E clouds is discussed.

We conclude that measurements of ion composition, electron temperature, electric current, and VLF noise in sporadic E clouds should provide valuable clues in the further understanding of the phenomenon.
4. Theories
Authors: Bowhill S. A.
Published: November 2015

In summarizing the status of the theory of the sporadic E layer it is necessary to distinguish four steps, on each of which it is necessary for the theoreticians to agree before it can he said that the problem is solved from a theoretical standpoint. These are as follows:
On the Point of Emergence of a Conical Microwave Beam Entering a Particular Nonuniform Plasma Column
Authors: Cullen A. L.
Published: November 2015

A circularly symmetrical conical wave, in which E., is the only component of the electric vector, is incident upon a circularly symmetrical plasma column of radius a in which the electron density is proportional to (a2/r2)‐1 for a radial distance r≤a, and is zero for r>a. The change in phase on reflection is determined as a function of the angle of incidence. A circularly symmetrical beam of radiation can be synthesized as an angular spectrum of conical waves, and the corresponding reflected beam is easily obtained in integral form. The position of maximum intensity in the reflected beam is found by making use of the principle of stationary phase.

The results obtained are compared with ray theory and with a previous calculation for a linear gradient of electron density in a planar geometry.
Electromagnetic Scattering by Loaded Wire Loops
Authors: Harrington Roger F. , Ryerson Joseph L.
Published: November 2015

The problem of electromagnetic scattering by circular wire loops loaded with lumped impedances along the wire is considered. A solution to the appropriate integral equation is obtained by a Fourier series method. The theory is valid for loops in arbitrary impressed fields, and for both monostatic and bistatic scattering. Previously obtained solutions for the loop antenna, the loaded loop antenna, and the unloaded loop scatterer are contained in the solution as special cases.
Analysis of a Double Discontinuity in a Coaxial Line
Authors: Hinchey F. A. , Prasad Sheila
Published: November 2015

This paper presents a field analysis of two closely spaced abrupt discontinuities in a coaxial transmission line. The discontinuities occur in the radius of the inner conductor of the transmission line.

The problem is formulated in terms of two simultaneous integral equations whose solution is obtained by a variational technique. The solution for the admittance is expressed in terms of an infinite series of field modes.

The first 11 mode amplitudes have been obtained numerically for different dielectrics and different radii, and admittances calculated. A comparison is made with the results obtained from a transmission‐line theory approximation.
Phase Height and the Ionospheric Valley Ambiguity
Authors: Paul Adolf K.
Published: November 2015

We consider whether a unique ionospheric electron density distribution can be calculated from ionograms in the case of a “valley” between the E and F regions, assuming that the absolute phase heights are available in addition to the virtual heights. By using the concept of an “equivalent distribution” it is shown that the additional knowledge of phase heights reduces the possible valley error, but cannot remove it completely.
Numerical Simulation of Ionospheric Wave Interaction Experiments (Digest of NBS Technical Note 325)
Authors: Georges T. M.
Published: November 2015

The need for an improved ground‐based radio technique for probing the lower ionosphere has prompted a number of experiments based on nonlinear radio wave interaction (ionospheric cross modulation or Luxembourg Effect) [Fejer, 1955: Rumi and Little, 1958: Barrington and Thrane, 1962: Ferraro et al., 1963: Smith, 1964]. Their success as accurate and continuous D‐region probes has been somewhat limited by the need for much greater experimental accuracy and sensitivity and an efficient method for interpreting interaction data in terms of electron density and collision frequency profiles. The solution of many of the problems in refining and optimizing this type of experiment and in the development of effective data reduction techniques depends ultimately on the formulation of a more comprehensive model of the interaction mechanism. This note summarizes a recent publication [Georges, 1965] which presents a simple method for simulating the interaction process on a digital computer. The technique is directly applicable to verticalincidence pulse interaction experiments based on the method of Fejer [1955], including cosmic noise interaction [Benson, 1962], phase interaction [Ferraro et al., 1963], and gyrointeraction [Smith, 1964]. By avoiding the explicit formulation and solution of closedform expressions for the interaction effects, many of the limitations and approximations involved in analytical treatments are bypassed. The simulation of many different interaction experiments using various theoretical models yields estimates of the limits of applicability of the simplified analytical theory, and shows that it becomes a poorer approximation as experimental conditions necessary for improved accuracy and sensitivity are approached. The numerical method also provides a basis for the development of an effective technique for the synthesis of ionospheric profiles from interaction data.
Quantitative Observations of Dot Angel Echoes at Two Frequencies
Authors: Deam Andrew P. , LaGrone Alfred H.
Published: November 2015

Results of many observations of radar echoes of the clear‐air dot angel type at Austin, Tex., are reported. Measurements were made at two wavelengths, $#x03BB;=3.3 em and $#x03BB;=9.1 em, using nearly identical antenna beams pointed vertically. Results suggest particulate matter, probably insects, as the source of most clear‐air dot angel echoes.

Other clear‐air angel‐type echoes which were observed on rare occasions are believed to originate at inversion layers. They were received only on S‐band and did not exhibit the same characteristics as most echoes of the dot angel type.
On Wave Propagation in Large Waveguides Containing Random Media
Authors: Chen Yung Ming
Published: November 2015

Propagation of time harmonic waves, either generated by random sources or scattered by smooth deterministic scatterers, is considered in large perfectly conducting waveguides which contain random media differing slightly from homogeneous media. Emphasis is given to computation of the mean values of wave motions and their physical interpretation. By perturbation theory, the original stochastic problem is first reduced to an equivalent deterministic boundary value problem, correct through terms of order ε2, where ε measures the deviation of the medium from homogeneity. then the equivalent problem is solved by methods of separation of variables and eigenfunction expansion. Upon utilizing the method of scattering amplitude, the obtained solutions are transformed into new representations, which not only provide excellent physical interpretation, but also play a key role in a new approximation technique for calculating the scattered waves in waveguides. Finally, the case of scattering by a small perfectly conducting sphere in a random rectangular waveguide is solved as a simple illustration.