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Purpose: Lung cancer is the second most common type of cancer prevalent in men worldwide. The early diagnosis of lung cancer can reduce cancer-related deaths considerably and increase the survival rate for a few years. In recent years, computer-aided detection (CADe) and computer-aided diagnosis (CADx) systems emerged as promising techniques for radiologists for the early diagnosis of lung cancer. An efficient pre-processing technique and accurate segmentation of the lung parenchyma in medical images will reduce false positives, which in turn can considerably improve the specificity of classification of the lung nodules as benign or malignant. Methods: A novel framework for preprocessing lung images and segmentation of the region of interest is proposed in this study. The noise removal in low-dose computed tomography (LDCT) images is performed by discrete wavelet transform with adaptive thresholding (DWTWAT). The segmentation of the lung region is performed by genetic algorithm enhanced K-means clustering (GAK-means) and genetic algorithm enhanced Fuzzy c-means clustering (GAFCM) in LDCT images. The segmentation is followed by lung reconstruction to preserve the juxta-pleural and Pleural tail nodules attached to the lung boundary. Results: The proposed methods were individually evaluated with the commonly used metrics of sensitivity, specificity, and accuracy. The novel noise removal technique of DWTWAT and segmentation with GAFCM has achieved a sensitivity, specificity, and accuracy of 99.54%, 99.99%, and 99.54%, respectively. The noise removal technique of DWTWAT for preprocessing and segmentation with GAK-means has achieved sensitivity, specificity, and accuracy of 99.47%, 99.77%, and 99.26%. Conclusion: The proposed techniques of noise removal and segmentation is a novel combination that showed improved results compared to the existing state-of-the-art method.

Background: Lung cancer has become a major cause of cancer-related deaths. Detection of potentially malignant lung nodules is essential for the early diagnosis and clinical management of lung cancer. In clinical practice, the interpretation of Computed Tomography (CT) images is challenging for radiologists due to a large number of cases. There is a high rate of false positives in the manual findings. Computer aided detection system (CAD) and computer aided diagnosis systems (CADx) enhance the radiologists in accurately delineating the lung nodules. Objectives: The objective is to analyze CAD and CADx systems for lung nodule detection. It is necessary to review the various techniques followed in CAD and CADx systems proposed and implemented by various research persons. This study aims at analyzing the recent application of various concepts in computer science to each stage of CAD and CADx. Methods: This review paper is special in its own kind because it analyses the various techniques proposed by different eminent researchers in noise removal, contrast enhancement, thorax removal, lung segmentation, bone suppression, segmentation of trachea, classification of nodule and nonnodule and final classification of benign and malignant nodules. Results: A comparison of the performance of different techniques implemented by various researchers for the classification of nodule and non-nodule has been tabulated in the paper. Conclusion: The findings of this review paper will definitely prove to be useful to the research community working on automation of lung nodule detection.

A diversity of reaction products have been found in the reactions of two related unsymmetrical Schiff base dinucleating ligands, HL¹ and HL², derived from 3-chloromethyl-5-methylsalicylaldehyde 1, with copper(II) and nickel(II) salts. The ligands remain intact in the copper(II) complexes to give the homodinuclear complexes [Cu₂L¹Br₃] 2 and [Cu₂L²(OH)(ClO₄)]ClO₄ 3, the crystal structures of which have been solved. The reactions of HL¹ and HL² with nickel perchlorate led to hydrolysis of the imine bond. With HL¹ the homodinuclear complex [NiL^A(OH₂)]₂[ClO₄]₂·4H₂O was formed and with HL² hydrolysis was followed by elimination of C₂H₄ from the terminal NEt₂ of the iminic side arm to leave an NHEt group and the dinuclear complex [NiL^C(OH₂)]₂[ClO₄]₂·3CH₃OH. The crystal structures of the two nickel complexes are also reported.

The reaction of 2‐benzylidene‐1,3‐diphenylpropanetrione (1a) with phosphorus ylides 2a–cafforded the new phosphonium ylides 4a–c. Trialkyl phosphites 3a–creact with 1ato give the respective dialkyl phosphonate products 5a–c. On the other hand, the olefinic compounds 6and 7were isolated from the reaction of 1bwith Wittig reagents 2. Moreover, trialkyl phosphites reacted with 1bto give products 8a–c. Possible reaction mechanisms are considered, and the structural assignments are based on analytical and spectroscopic evidence. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:57–64, 2000

Lawesson's reagent (1a) reacts with pyrogallol (2) to give 1,3,2‐benzodioxaphospholane‐2‐sulfide (3) and with 1,8,9‐trihydroxyanthracene to give 13. The structures of the products have been established either chemically, using methanolysis and methylation, or spectroscopically. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 25–30, 1999

Mixed oligomeric five-membered heteroarylenes 3a-f and 4a-e have been prepared by cross-coupling reaction of the Grignard reagents 2 derived of the appropriately substituted thiophenes 1 with either the 2-bromoheteroarylenes or the 2,5-dibromoheteroarylenes derived of furan, thiophene, and/or selenophene respectively. The UV spectra and oxidation potential of compounds 3a-f and 4a-e are discussed on the basis of co-planarity.

The reaction between nitriles and O,O-dialkyldithiophosphoric acid (2) under anhydrous conditions produces O,O-diethyl-N-thiobenzoylamidophosphate (5), contrary to literature. When water is present the same reaction gives the corresponding thioamides in reasonable to good yields. Mechanistic considerations and spectral data are presented for the products.

Benzenesulfenyl chloride, a soft electrophile, reacts with 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithia-diphosphetane 2,4-disulfide (LR) on sulfur to give S,S-phenyl (4-methoxyphenyl) phosphonochloridothiolothionate (3) as an intermediate. Compound 3 reacts with nucleophiles as sodium alkoxides or amines to give good yields of S,S-phenyl O-alkyl(4-methoxyphenyl) phosphonothiolothionate (4) and S,S-phenyl (4-methoxyphenyl) phosphonopyrrolidinothiolothionate (6), respectively.

2,4-Bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide, 1, reacted with ketoximes at 25° followed by alkylation with methyl iodide to give oximino-4-methoxyphenyl-S-methyl-phosphonodi-thoate, 4. p-Tolualdehyde oxime when treated with 1 gave 2,4,6-tri-p-tolyl-1,3,5-trithiolidine, 6. The reaction of benzohydroxamoyl chlorides with 1 yielded 1,3,5,2-oxathiazaphospholes, 8, whereas p-nitrobenzohydroxamoyl chloride gave 3,6-di(4-nitrophenyl)-1,4,2,5-dioxadiazine, 11. Diarylketoximes with 1 produced 13 and 14. 9-Benzanthrone oxime with 1 afforded 9-benzanthrone thione, 16. The reaction of oximes of phenyl phenylmethylketoximes or 1,3-diphenyl-2-propanone with 1 at 80° afforded 1,3,2-thiazaphospholines, 18.

1,3,2,4-Dithiadiphosphitane-2,4-bis(4-methoxyphenyl)-2,4-disulfide (1) reacts with acenaphthenequinone (2) to give acenaphthenenone-2-thione (3). Compound 1 also reacts with isatins (6a, 6b) to yield isoindigotine (7a) and dimethylisoindigotine (7b) respectively. Isoindigotine upon reacting with 1 gives [δ3,5-biindoline]-2,2'-dithione (8). Thiation of anthraquinone (9) with 1 leads to the formation of 10-monothioanthraquinone (10). [δ9,9'(10H,10'H)-Bianthracene]-10,10'-dithione (11) is obtained via thiation of 10-diazoanthraquinone (12) or bianthraquinone (13) with 1. Structural assignment are based on analytical, chemical and spectroscopic evidence.

Diethyl phenylphosphonite and ethyl diphenylphosphinite react with 2- benzylideneindan-1,3-dione(1) to give colourless addition compounds (6) and (8) respectively. The reaction of diethyl methyl phosphite and ethyl dimethyl phosphite with (1) leads to the formation of the corresponding phosphonates (9) and (11). Possible reaction mechanisms are considered and the structural assignments are based on chemical and spectroscopic evidence.

Mixed oligomeric 2,2'- and 2,2'-5',2''-unsubstituted five-membered heteroarylenes containing furan, thiophene, and selenophene rings 2a-f and 3a-i have been synthesized. Their UV spectra and oxidation potentials are discussed.

Abstract: Systematic studies were carried out on the extraction of U(VI), Th(IV) and Ce(III) with HDEHP from pure hydrochloric and sulfuric acid solutions as well as from their binary mixtures. The influence of water-miscible alcohols and acetone on the extraction of these elements was also investigated. Results were discussed and procedures for the separation of the concerned elements have been recommended. A suggested extraction mechanism is presented in the light of the obtained results.

Abstract: Sorption of Th, Pa, U, Np and Pu on silica gel from HNO3, HCl and HCl−ROH solutions was investigated. Equilibrium studies indicated sorption behaviour to vary greatly with the acid used. In mixtures of HCl with different alcohols, distribution coefficints were found to depend on alcohol percentage as well as on acidity. Results were discussed and conditions for possible separations were indicated.

Abstract: The adsorption behaviour of thorium, protactinium, uranium, neptonium and plutonium on zirconium phosphate from nitric acid and ammonium nitrate solutions was investigated. Partition data from the mentioned media together with that from chloride solutions were used to calculate formation constants for the concerned elements in the range of Cl− and NO 3− activities <1M. Obtained β values were compared with those reported in the literature and indicated reasonable agreement.

Abstract: A systematic study is presented on the extraction of Zr(IV) by tri-n-butylphosphate from H2SO4, HNO3, HCl and HBr solutions as well from binary mixtures of H2SO4 and halogen acids. It has been found that Zr(IV) extraction is appreciably increased by addition of halogen acid to sulphuric acid solutions. On the other hand, the presence of water-miscible alcohols and acetone was found to enhance Zr(IV) extraction from HCl and HNO3 solutions. An investigation of extracted Zr complexes from pure acids and mixed aqueous media enabled an explanation of the observed enhancements. In the light of the obtained results, an extraction mechanism is suggested.

Abstract: The extraction of hydrochloric, nitric, and sulphuric acids with TBP was studied as a function of methanol, ethanol, isopropanol, and acetone concentration in the aqueous phase. Extraction increases in the order: methanol

Abstract: Studies on the extraction of thorium, protactinium, uranium and neptunium from H2SO4 solutions by TLA indicated that these elements have low distribution coefficients (<0.1) at high acid concentrations. Additions of HCl or HBr to H2SO4 solutions enhances appreciably the extraction of the mentioned elements. A systematic investigation on the effect of halide concentration and solvetn concentration helped in explaining the observed enhancement as well as identifying the extracted complexes.

Abstract: The effect of TBP as well as the organic diluents on the polarographic wave of U(VI) reduction has been investigated in sulphuric and perchloric acids. It was found that the presence of TBP traces in the solution to be analyzed induced another wave which was more prominent in sulphuric acid solutions. This can be eliminated by boiling the solutions for about 5 min before their analysis for uranium. The effect of supporting electrolyte on the polarographic reduction of U(VI) was also studied and the use of 6N HClO4 was recommended.

Lawesson's reagent (1a) reacts with pyrogallol (2) to give 1,3,2-benzodioxaphospholane-2-sulfide (3) and with 1,8,9-trihydroxyanthracene to give 13. The structures of the products have been established either chemically, using methanolysis and methylation, or spectroscopically. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 25–30, 1999

A large global land area is affected by saline, alkali (sodic), and acid soil conditions. Cool season food legumes are important crops in many countries with such adverse soils. Tolerant genotypes have been identified in many crops, including legumes. However, very little has been published on selection of tolerant cool season food legume crops. The inadequate knowledge and understanding of the responses of cool season food legume crops to these abiotic stresses, necessitates action by a collaborative network of interdisciplinary teams to make rapid progress in identifying tolerant germplasm and developing cultivars better adapted to unfavorable soil conditions.

The syntheses of 3-substituted long-chain furans and thiophenes by a Wittig reaction are described. 1H-NMR and UV data of these compounds are reported.

Naphthalenone 1 reacts with thiol phosphoric acids 3 and 6 to give adducts 5 and 7, respectively. Reaction of 1 with Lawesson reagent 8 and P4S10 gives adducts 9 and 10, respectively. On the other hand, reaction of naphthalenone 2 with reagent 3 and 6 leads to the formation of adducts 11 and 12, respectively. Thiation of 2 with 8 or P4S10 yields the dimeric adduct 14. The identity of the new products is established from analytical and spectroscopic evidences.

Wittig reagents (Ia-c) react with hexahydro-1,3-phthalandione (II) yielding the new adducts (IIIa-e). The structure of these products were established by analytical and spectroscopic methods. A mechanism is proposed to explain the formation of the new ylid-phosphorane adduct IIIa.

Some hindered bithienyl derivatives have been synthesized by cross-coupling reaction of Grignard reagents using NiCl2(dppp)(dppp = Ph2PCH2CH2CH2PPh2) or by reductive dimerization in the presence of Zn/NiCl2(PPh3)2. Their UV spectra and oxidation potentials are discussed in terms of their coplanarity and of the inductive effect of the substituent.

Sodium alkoxide, a hard nucleophile, reacts with 2,4-bis(4-methoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (LR) on phosphorus to give O-alkyl S-sodium-(4-methoxyphenyl) phosphonothiolothionate 5 as an intermediate. Compound 5 reacts with benzyl (or benzoyl) chloride to give good yields of O-alkyl S-benzyl (benzoyl) (4-methoxy-phenyl)phosphonothiolothionate (6a-e).

Di-, and trimethylphosphites react with enaminolactone, 4, only in methanol to give N-benzoyl-3-phenyl-3-phosphonoalanine-trimethylester (7) in good yields. Diphenylphosphinodithioic acid also reacts with 4 to give N-benzoyl-3-phenylcysteine-methyl ester-diphenylphosphinodithioate (9). A mechanism is proposed to account for the formation of 7. Compatible analytical and spectroscopic results were obtained for the new compounds.

1,3,2,4-Dithiadiphosphetane 2,4-disulfides 1a,b react with benzilmonoanils 2a-d to give 4,5-diphenyl δ4-1,3,2-thiazaphospholine-2-sulfide derivatives of type 3. Compatible analytical and spectroscoptic results were obtained for all the new compounds. A mechanism is proposed to explain the formation of compounds 3.

Selection for yield (10% intensity) was carried out in two groups of random oat (Avena salivaL.) lines (group T and group G contained 200 and 480 lines, respectively) under low‐, medium‐, and high‐productivity conditions. Selected lines from each selection condition were tested for mean, response, and stability of yield, in evaluation experiments that encompassed production environments from low to high. Actual gains in mean yield from selection averaged across the three selection environments were 16 and 7% in the T and G groups, respectively. Actual advances were 16, 13, and 18% of the population mean under low, medium, and high productivity, respectively, for group T, and 7, 5, and 8%, respectively, for group G. In each group, advances from selection under high and low productivities were superior to that from medium productivity. There was no superiority for one selection condition over another for either response or stability of yield. Lines selected onlyunder low or medium productivity gave mean yields not significantly greater than the respective group means, whereas those selected onlyunder high productivity gave significantly greater ones. The number of lines common to the samples selected under low, medium, and high productivity were three for group T and six for group G. These lines averaged 20% greater than the group means for yield, and were significantly superior under low, medium, and high productivity. Low‐ and high‐productivity conditions were nearly equal for selecting high‐yielding lines of oats, and both were somewhat superior to medium productivity. However, a detailed analysis showed that high productivity tended to differentiate high‐yielding lines best. The most superior lines for all conditions of production were those chosen in all three selection environments and those chosen in both low and high productivity.

Abstract: Extraction of WO 42– and ReO 4– by Adogen-381, tricaprylmethylammonium chloride, Hyamine 10-X, trioctylphosphine oxide or dibenzylsulphoxide in xylene from HNO3, HCl or H2SO4 acid medium was investigated. Based on the separation factors obtained, the separation of ReO 4– from WO 42– was elucidated. ReO 4– was separated from WO 42– in high radiochemical purity: >99.9% by three successive extractions and strippings using Adogen-381 from HCl or HNO3 acid medium.

Abstract: The distribution of UO 22+ , Ce3+ and Am3+ between Chelex-100 and 0.2 and 5.0M ammonium thiocyanate solutions of different hydrogen ion concentrations has been investigated. The results obtained are compared with parallel experimental results using the anion exchanger Dowex-1×4 and the cation excharger Dowex-50×8. It is found that Chelex-100 can act as anion exchanger at pH<2 and as cation and chelate exchanger at higher pH. A main feature of the distribution results of UO 22+ , Am3+ and Ce3+ with Chelex-100 is the very high distribution coefficient for the three cations at pH higher than 3.5 from aqueous solutions containing 0.2 or 5.0M ammonium thiocyanate.

Abstract: The extractability of selenium halides with benzene and some of its derivatives has been investigated using a radioactive tracer technique in order to establish the optimum conditions for its extraction. It has been found that Se(IV) is poorly extracted from HCl, HBr or H2SO4 solutions but high distribution ratios are observed with binary mixtures of 9M H2SO4 and acid halides. The extraction of some other elements is also studied under the conditions selected for Se(IV) extraction and it has been found that only antimony follows Se(IV) in the organic phase. In view of the data obtained, analytical advantages are mentioned and separation procedures are recommended. The extraction mechanism is also discussed and the role of sulfuric acid in the extraction system is explained.

Abstract: Systematic studies are carried out on the extraction of tri-and pentavalent antimony with MIBK from pure acid halide solutions as well as from binary mixtures of each with sulphuric acid. The influence of KI on the extraction of antimony from sulphuric acid is also investigated. It is found that the extraction of antimony halides is highly affected by addition of sulphuric acid to the aqueous phase. The extractability of some other elements at the optimum conditions for antimony extraction is also studied in order to establish separation procedures. In the light of the obtained results, analytical advantages are mentioned and separation procedures are recommended. The extraction mechanism is also discussed in order to explain the role of sulphuric acid in the extraction equilibria.

Abstract: Systematic studies are carried out on the distribution of Pu(IV), Am(III) and Cm(III) from nitric acid media using solid (Dowex) and liquid (TCMA) anion exchangers. The distribution of these elements from nitric acid-organic solvent mixtures is also investigated. In view of the given results, convenient procedures for interseparation of the mentioned elements are recommended.

Abstract: A systematic study was carried out on the adsorption behaviour of Na, Cs and Ba on Dowex 1X8 from various concentrations of hydrochloric and nitric acid solutions. The addition of water-miscible organic solvents to the acidic solutions was found to increase the Kd values for these elements to different extents, which provides a useful method for the separation of carrier-free Ba from irradiated Cs. The effect of kind and content of the different alcohols on the adsorption of Ba was also investigated. It was found that Kd increases with the increase of the alcohol content as well as with the increase of both the dielectric constant and chain length of the alcohol. This effect was found to be more pronounced in the case of nitric acid media.

Abstract: Anion exchange separation of Ga-In on Dowex 1 resins of 2, 4, 8, and 10 nominal cross-linkings, respectively, was investigated at tracer loadings. The influence of temperature on the exchange reaction was also studied on the different resins. Separation factors, plate heights, and resolutions for the two peaks were calculated from the elution curves. Best separations were achieved with Dowex 1X4 due to the most promising values for both plate height and resolution. It was also found that the separation factors as well as the plate heights decreased with growing temperature.

A convenient synthesis of a number of oligomeric thiophcnes and oligomeric methyl-, and ethyl-substituted thiophenes as building blocks for novel conducting polymers is reported. The synthesis is based on a NiCl2(dppp) (dppp = Ph2PCH2CH2CH2;PPh2) catalyzed coupling reaction between appropriately substituted bromothiophenes and Grignard compounds derived of them. The λmax of the UV spectra of the unsubstituted oligomeric thiophenes increases, as expected, with the number of thiophene units in the oligomers. Also, as expected, the oxidation potential Emax of these compounds decreases with increasing the number of thiophene units. In the series of the methyl- or ethyl-substituted oligomeric thiophenes such a clear cut relationship is not observed. This behavior is discussed on the basis of diminishing coplanarity due to steric hindrances by the alkyl groups in the 3,3'-positions, which results in a blue shift of the λmax of the UV spectra and a decreased stability of the radical cation formed upon electrooxidation, manifesting itself by a higher oxidation potential.

Lawesson's reagent (LR) reacts with 1,2-phenylenediamine derivatives (2a-c) to give 1,3-dihydro-1,3,2-diazaphosphole-2-sulfide (3a-e). Also it reacts with 2-aminophenol (4) and 2-amino-2-methyl-1-pro-panol (6) to give 1,3,2-oxazaphospholes 5, 7 respectively.

1,3,2,4-Dithiadiphosphetane-2,4-disulfide (Lawesson reagent, 1a) and its p-phenoxy derivative, 1b react with benzil dianils 2ab, in refluxing toluene to give 2H--1,3,6,2-thiadiazaphosphorine-2-sulfide derivatives of type 3a-c. Compatible analytical and spectroscopic results were obtained for the new compounds. A mechanism is proposed to explain the formation of compounds 3a-c.

Protactinium is highly extracted by tetraphenylarsonium chloride from hydrochloric acid solutions, but niobium and zirconium are extracted as well. The three elements have rather low extractabilities from hydrobromic acid solutions and sulfuric acid solutions. In mixtures of (HCl + H2SO4) or (HBr + H2SO4), protactinium indicates high distribution coefficients, while niobium and zirconium have again rather low or negligible extractabilities. Results were discussed and data were used to suggest selective conditions for the separation of the three elements.

The problem of contamination of tartar emetic with arsenic and lead was examined using the radioactive isotopes, 76As and 209Pb. Neutron activation and radiochemical separation methods have been applied for the determination of arsenic and lead concentrations throughout the different stages of tartar emetic synthesis. It has been shown that, while most of arsenic is eliminated during the synthesis process, the major portion of lead remains in the final product. It was also found that the two impurities can be eliminated by successive washing of the starting materials with 0.2 Mnitric acid and water. Tartar emetic synthesized from purified starting materials conforms to the requirements in pharmacopeias.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.