bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do antidepressants cause suicidality in children? A Bayesian meta-analysis
Authors: Kaizar Eloise E , Greenhouse Joel B , Seltman Howard , Kelleher Kelly 
Published: May 2006

Background To quantify the risk of suicidal behavior/ideation (suicidality) for children who use antidepressants, the FDA collected randomized placebo-controlled trials of antidepressant efficacy in children. Although none of the 4487 children completed suicide, 1.7% exhibited suicidality. The FDA meta-analyzed these studies and found sufficient evidence of an increased risk to require a black-box warning on antidepressants for children. Purpose The FDA considered different drug formulations and psychiatric diagnoses to be equivalent in their effect on suicidality. If this assumption does not hold, the FDA analysis may have underestimated the variance of the risk estimate. We investigate the consequences of relaxing these assumptions. Methods We extend the FDA analysis using a Bayesian hierarchical model that allows for a study-level component of variability and facilitates extensive sensitivity analyses. Results We found an association between antidepressant use and an increased risk of suicidality in studies where the diagnosis was major depressive disorder (odds ratio 2.3 [1.3, 3.8]), and where the antidepressant was an SSRI (odds ratio 2.2 [1.3, 3.6]). We did not find evidence for such an association in the complement sets of trials. Although the results based on the hierarchical model are insensitive to model perturbations, the robustness of the FDA's meta-analysis to model assumptions is less clear. These data have limited generalizability due to exclusion of patients with baseline risk of suicide and the use of relatively short duration trials. Conclusions Because of model specification and interpretation issues raised in this paper, we conclude that the evidence supporting a causal link between antidepressant use and suicidality in children is weak. The use of Bayesian hierarchical models for meta-analysis has facilitated the incorporation of potentially important sources of variability and the use of sensitivity analysis to assess the consequences of model specifications and their impact on important regulatory decisions.
Benchmarks for designing two-stage studies using modified mini-mental state examinations: experience from the Women's Health Initiative Memory Study
Authors: Espeland Mark A , Rapp Stephen R , Robertson Julia , Granek Iris , Murphy Carol , Albert Marilyn , Bassford Tamsen 
Published: May 2006

Background The most efficient approach for studies examining the incidence of dementia involves a brief screening instrument to identify participants for more extensive testing to identify cognitive impairment. The modified mini-mental state examination (3MS) is commonly used as this initial screen in such two-stage designs, however its properties for this role require further study. Purpose We use data from the Women's Health Initiative Memory Study to contrast design options in two-stage designs. Methods This trial enrolled 7251 participants with nine or more years of education who were aged 65–79 and followed an average of four to five years. Logistic regression was used to examine the case yields at varying two-stage 3MS cutpoints. The efficiency of using different examination schedules and restricting enrollment to higher risk women was examined. Results Probable dementia is associated with marked decline in 3MS scores. The percentages of women classified with probable dementia ranged from 7.95% (3MS 85–88) to 50.0% (3MS = 70). The numbers [95% confidence interval] of enrolled women necessary to detect one case of probable dementia (four-year follow-up) for baseline 3MS scores of 100, 95, 90 and 85 were estimated as 1477 [389, 5618], 253 [134, 481], 53 [34, 85], and 14 [9, 23], respectively. Compared to annual testing, administration every two years increased the number of required enrollees by 11%, but decreased the number of test administrations by 46%. Limitations Our findings are influenced by the characteristics of our study group, its rates of retention, and the study protocol, and may not fully generalize to other settings. Conclusions The 3MS can serve as an efficient basis for two-stage study designs and a cutpoint of 88 is reasonable for populations with similar characteristics. Studies may improve efficiency by using the 3MS during screening to eliminate women with low risk for dementia and by conducting testing every two years.
Effectiveness of strategies to recruit underrepresented populations into cancer clinical trials
Authors: Lai Gabriel Y , Gary Tiffany L , Tilburt Jon , Bolen Shari , Baffi Charles , Wilson Renee F , Howerton Mollie W , Gibbons M Chris , Tanpitukpongse Teerath Peter , Powe Neil R , Bass Eric B , Ford Jean G 
Published: May 2006

Background Certain populations, including racial and ethnic minorities and older persons, have had a history of low participation in cancer-related trials, yet there has been little information reported on recruitment strategies tailored to improve their enrollment. Methods We conducted a systematic literature review to examine the methods used to study recruitment of underrepresented populations into cancer prevention and treatment trials and examined the studies that compared the efficacy and/or effectiveness of different recruitment strategies. We performed an electronic search through multiple databases including PubMed and a hand search of 34 journals. Potential studies were pulled and underwent title, abstract, and article review by at least two investigators. Results Fourteen articles examined recruitment of underrepresented populations into cancer trials and, of these, five compared efficacy or effectiveness of different strategies for recruitment of underrepresented populations into randomized or concurrent controlled trials. These five studies used various strategies but only three reported that specific recruitment strategies, such as media campaigns and churchbased project sessions, resulted in improvement in accrual to cancer trials. Conclusion There is limited evidence for efficacious or effective strategies to recruit underrepresented populations in cancer-related trials. The available evidence cannot be generalized to these heterogeneous groups. Further study is needed on efficacious strategies for recruitment of underrepresented populations into cancerrelated trials.
Walking byIxodes ricinusticks: intrinsic and extrinsic factors determine the attraction of moisture or host odour
Authors: Crooks Emily , Randolph Sarah E. 
Published: May 2006

SUMMARYSpontaneous walking by Ixodes ricinus nymphs in the horizontal plane was investigated within choice arenas to test whether these ticks move preferentially up a humidity gradient, and whether they are attracted towards host odour, specifically volatile substances from the back of a dog's ear. Responses by ticks with high and low fat contents and in different states of hydration were compared. Ticks with higher energy reserves were more likely to walk horizontally over short distances. Only if they were slightly dehydrated were they more likely to walk towards fully saturated air than drier air, and only if the atmosphere was sufficiently wet were they likely to walk towards odour secreted by host skin. It seems that, under certain circumstances, ticks of this ambushing species will move short distances towards host odour.
Temperature Dependence of Mixed-Valence States in Solvated and Non-Solvated Trinuclear Iron Stearates
Authors: Nakamoto Tadahiro , Katada Motomi , Sano Hirotoshi 
Published: May 2006

Abstract
Solvated and non-solvated mixed-valence trinuclear iron stearates were prepared and their Mössbauer spectra were determined. XRD patterns of the compounds show that they have layer structures having different inter-layer distances. A temperature-dependent mixed-valence state was observed in the non-solvated compound, while not in the solvated compound.
Allyltris(trimethylsilyl)silane as Radical Allylating Agent for Organic Halides
Authors: Kosugi Masanori , Kurata Hiroshi , Kawata Ken-ichi , Migita Toshihiko 
Published: May 2006

Abstract
Reaction of allyltris(trimethylsilyl)silane with organic halides under the free radical conditions resulted in allylation of the halides in modrate to good yields. The presence of three trimethylsilyl groups on the silicon could enhance the homolytic dissociation of a Si–C bond in the β-silylalkyl radical.
Oxidation of Uranium(IV) by Nitrite Ion in Dimethyl Sulfoxide. Evidence of Direct Oxygen Transfer Mechanism
Authors: Park Yoon-Yul , Ikeda Yasuhisa , Harada Masayuki , Tomiyasu Hiroshi 
Published: May 2006

Abstract
The oxidation of [U(dmso)8]4+ (dmso = dimethyl sulfoxide) by nitrite ion was studied in dmso. The reaction was found to proceed via two steps: the first step was the rapid formation of 1 : 2 complex between U(IV) and nitrite ion, and the second one the intramolecular oxygen transfer reaction from nitrite to U(IV). The latter step was confirmed by oxygen labeled experiments using 17O-NMR.
Unexpected Thermal Rearrangement of N-[1-Methyl-6-(methoxycarbonyl)-5-hexynylidene]methylamine N-Oxide
Authors: Kang Han-Young , Cho Yong Seo , Koh Hun Yeong , Chang Moon Ho 
Published: May 2006

Abstract
N-[1-Methyl-6-(methoxycarbonyl)-5-hexynylidene]methylamine N-oxide, a ketonitrone which was prepared from the reaction between methyl 7-oxooct-2-ynoate and N-methylhydroxylamine rearranged thermally into two isomeric bicyclic compounds instead of the expected intramolecular [3+2] cycloadduct. Also an aldonitrone, N-[6-(methoxycarbonyl)-5-hexynylidene]methylamine N-oxide provided the corresponding rearranged product.
Photoinduced Electron-Transfer Reaction in a Zinc Myoglobin–Hexacyanoferrate(III) Complex
Authors: Tsukahara Keiichi , Asami Satoko 
Published: May 2006

Abstract
The photoinduced electron transfer was observed in a zinc myoglobin–hexacyanoferrate(III) complex, which forms by electrostatic interactions, and was inhibited in addition of poly-L-lysine by forming a stable complex of poly-L-lysine and hexacyanoferrate(III) ions.
The Asymmetric Diels–Alder Reaction of α,β-Unsaturated Aldehydes with Dienes Using a Chiral Boron Reagent as a Catalyst
Authors: Kobayashi Shu , Murakami Masatoshi , Harada Tsunehiro , Mukaiyama Teruaki 
Published: May 2006

Abstract
The asymmetric Diels–Alder reaction of α,β-unsaturated aldehydes with cyclopentadiene is catalyzed by a novel chiral boron reagent generated in situ from boron tribromide and a chiral prolinol derivative, to afford the corresponding adducts in good yields with fairly good to excellent ees.
Synthesis and Structural Analysis of Dimethoxy[2.n]metacyclophanes
Authors: Okada Yukihiro , Mabuchi Shunsuke , Kurahayashi Masaki , Nishimura Jun 
Published: May 2006

Abstract
Dimethoxy[2.n]metacyclophanes were obtained in 46–68% yields through [2 + 2] photocycloaddition of corresponding styrene derivatives. These metacyclophanes were assigned to be of syn-conformation (n = 3, 4, 5, and 6) or the mixture of syn- and anti-conformers with the syn/anti ratio of 4/3 (n = 2).
Facile Synthesis of α-Hydroxybutenolides and α-Keto-β-allyl-γ-butyrolactones
Authors: Shimizu Isao , Maruyama Takashi , Hasegawa Hajime 
Published: May 2006

Abstract
The reaction of α-keto-β-alkyl-β-allyloxycarbonyl-γ-butyrolactones with ammonium formate in the presence of palladium catalyst gave α-hydroxybutenolides in good yields. When the reaction was carried out without ammonium formate, decarboxylation-allylation took place to give allyl enol ethers of α-hydroxybutenolides, which were converted to α-keto-β-allyl-γ-butyrolactones by the thermal Claisen rearrangement.
Alignment of Liquid Crystal on the Conductive Pyrolyzed Polyimide Langmuir–Blodgett Films
Authors: Akatsuka Takahisa , Tanaka Hideaki , Toyama Jiro , Nakamura Takayoshi , Matsumoto Mutsuyoshi , Kawabata Yasujiro 
Published: May 2006

Abstract
Highly conductive pyrolyzed polyimide Langmuir–Blodgett (LB) films showed good aligning properties for a twisted nematic liquid crystal. Static and dynamic alignment properties of the LB films were similar to those of rubbed polyimide films on ITO electrodes.
Synthesis of Benzo[c]quinolizinium Salts by Photocyclization
Authors: Arai Sadao , Tabuchi Kunihisa , Arai Hitoshi , Yamagishi Takamichi , Hida Mitsuhiko 
Published: May 2006

Abstract
The photocyclization of 2-[2-(2-chlorophenyl)vinyl]-6-methylpyridine and 2-[2-(2-chlorophenyl)vinyl]quinoline in acetonitrile afforded new compounds 1-methylbenzo[c]quinolizinium salt and dibenzo[c,f]quinolizinium salt in 56% and 41% yields, respectively.
Reactions of Ethynylcarbenes Related to Solid-State Polymerization of 1-Phenyl-1,3-butadiyne
Authors: Koga Noboru , Matsumura Masahiro , Noro Masaki , Iwamura Hiizu 
Published: May 2006

Abstract
1,8-Diphenyl-1,8-bis(diazo)-octa-4-ene-2,6-diyne was prepared and photolyzed to give 1-phenyl-1,3-butadiyne in high yield. Ethynylphenylcarbene and β-phenylethynylcarbene generated by photolysis in MTHF at 6 K are in equilibrium in which the latter predominates at 90 K.
Synthesis and Radical Polymerization of Adamantyl-Containing Maleic and Fumaric Esters Leading to Formation of Thermally Stable Poly(substituted methylene)s with a Rigid Chain Structure
Authors: Matsumoto Akikazu , Otsu Takayuki 
Published: May 2006

Abstract
Several dialkyl maleates and fumarates bearing 1-adamantyl and 3,5-dimethyl-1-adamantyl groups were prepared and polymerized with a radical initiator, resulting in formation of high molecular weight and thermally stable poly(substituted methylene)s with a rigid chain structure.
A New and Stereoselective Synthetic Route to an Amaryllidaceae Alkaloid, (±)-Lycorine
Authors: Hoshino Osamu , Ishizaki Miyuki , Kamei Keisuke , Taguchi Minoru , Nagao Takashi , Iwaoka Kiyoshi , Sawaki Shohei , Umezawa Bunsuke , Iitaka Yoichi 
Published: May 2006

Abstract
Formal and total syntheses of an Amaryllidaceae alkaloid, (±)-lycorine, were achieved by a new synthetic route via (±)-3-(phenylseleno)-seco-dihydro-B-norlycorin-5-one.
Induction of Left-Handed Helical Arrangement of 4-Nitrobenzyl Ester Residues in Cast Film from Poly(L-Glutamate) by Using a Cationic Bilayer Forming Compound
Authors: Hirayama Chuichi , Ihara Hirotaka , Shiraga Ryuichi 
Published: May 2006

Abstract
Poly(γ-4-nitrobenzyl L-glutamate) provided S-chirality with strong exciton coupling in cast film by using dihexadecylammonium bromide (2C16N+2C1) as an additive. The X-ray and IR spectra showed that the main chain formed helices. The addition of 2C16N+2C1 induced a left-handed helical conformation of the main chain, along which the chromophoric residues were helically arranged.
Chemiluminescence of Tryptophan with Electrogenerated Tris(2,2′-bipyridine)ruthenium(III)
Authors: Uchikura Kazuo , Kirisawa Makoto 
Published: May 2006

Abstract
A system for electrogenerated chemiluminescence based on the reaction of electrogenerated Ru(bpy)33+ with tryptophan (Trp) is described. The orange chemiluminescence was generated by reaction of Ru(bpy)33+ with Trp in acidic solution. The lowest detection limit was 0.1 pmol for Trp. This newly demonstrated system should prove useful for the selective and sensitive detection of Trp.
α-Methylene Cyclic Carbonate as a Conjunctive Agent for Aromatic Aldehydes
Authors: Inoue Yoshio , Matsushita Koichi , Yen I-Fang , Imaizumi Shin 
Published: May 2006

Abstract
α-Methylene cyclic carbonate underwent decarboxylative cycloaddition to aromatic aldehydes to yield dihydrofuranone derivatives in the presence of a dicationic palladium complex.
A Convenient Route for the Synthesis of 2-C-Substituted 2-Deoxyhexoses
Authors: Sugimura Hideyuki , Osumi Kenji , Koyama Tatsuyuki 
Published: May 2006

Abstract
A facile method has been developed for the synthesis of 2-C-substituted 2-deoxy-D-glucoses and 2-C-disubstituted 2-deoxy-D-arabino-hexoses using the BF3-catalyzed cyclization between 1-alkenyl ethers and 2,3-O-isopropylidene derivative of aldehydo-D-erythrose.
Synthesis and Properties of Optically Active α-Aryl-γ-alkyl-γ-lactones as Chiral Dopants for Ferroelectric Liquid Crystals
Authors: Sakaguchi Kazuhiko , Kitamura Tohru , Shiomi Yutaka , Koden Mitsuhiro , Kuratate Tomoaki 
Published: May 2006

Abstract
Optically active α-aryl-γ-alkyl-γ-lactones were synthesized from chiral epichlorohydrin in several steps and found to be good chiral dopants for ferroelectric liquid crystals (FLCs). Relationship between molecular structures and properties is discussed.
Crystalline Complexes of Acyclic p-Cresol-Formaldehyde Tetramer with Benzene. An Induced Fit Type Binding of Benzene Molecule
Authors: Usui Shuji , Deyama Kazuhito , Fukazawa Yoshimasa , Sone Tyo , Ohba Yoshihiro 
Published: May 2006

Abstract
An acyclic p-cresol-formaldehyde tetramer (1) has syn-anti arrangement of cresol units and forms “partial cone” type cavity. A benzene is included in the cavity composed of the two facing partial cones. While 1 forms cyclic dimer via intra- and intermolecular hydrogen bondings, its dibromo derivative forms acyclic dimer with anti-anti arrangement of cresol units.
Solid-State Organic Reactions Proceeding by Pulverization of Inorganic Solid-Supports. Reactions of lodosobenzene with Unsaturated Hydrocarbons on Acid-Treated Silica Gel
Authors: Sohmiya Hajime , Kimura Takahide , Bauchat Patrick , Fujita Mitsue , Ando Takashi 
Published: May 2006

Abstract
Pulverization of solid mixtures of hydrogen halide-treated silica gels, iodosobenzene, and alkenes or an alkyne in the absence of a solvent brings about smooth and rapid reaction to give halogenated or oxidized products in good yields.
Synthesis and Magnetic Property of Imidazolate-Bridged Trinuclear Cu(II)–Fe(III)–Cu(II) Complexes. Effect of Fe(III) Spin-State Upon Spin-Coupling
Authors: Matsumoto Naohide , Tamaki Hiroko , Inoue Keiji , Koikawa Masayuki , Maeda Yonezo , Okawa Hisashi , Kida Sigeo 
Published: May 2006

Abstract
Imidazolate-bridged trinuclear Cu(II)–Fe(III)–Cu(II) complexes [Cu(A)Fe(acen)Cu(A)]ClO4·2H2O (1) and [Cu(A)Fe(salen)Cu(A)]ClO4·2H2O (2) are synthesized and characterized by magnetic susceptibilities, Mossbauer spectra, and ESR spectra, where H2A = 4-(6-methyl-8-oxo-2,5-diazanonane-1,5,7-trienylimidazole. The Fe(III) of 1 is in low-spin state (S = 1/2) and the spin-coupling between the Fe(III) and Cu(II) ions is ferromagnetic. On the other hand, the Fe(III) of 2 is in high-spin state (S = 5/2) and the spin-coupling is antiferromagnetic.
Cobalt-Catalyzed Photochemical Carbonylation of Allylic Amines
Authors: Mori Sadayuki , Matsuyoshi Hiroaki , Kudo Kiyoshi , Sugita Nobuyuki 
Published: May 2006

Abstract
Allylic amines are carbonylated at room temperature in the presence of cobalt catalysts under UV irradiation. With allylamine, 2-pyrrolidone, N,N′-diallylurea, and N-allyl-3-butenamide were obtained. The photochemical cleavage of C–N bond of amines coordinated to cobalt metals was suggested.
Unusual Differences between the Average Mn–Se and Mn–S Distances and between Se–C and S–C Distances in (NMe4)2[Mn(QPh)4] (Q = Se, S)
Authors: Ueyama Norikazu , Kajiwara Atsushi , Yasuoka Noritaka , Nakamura Akira 
Published: May 2006

Abstract
Crystal structures of (NMe4)2[MnII(SePh)4] and (NMe4)2[MnII(SPh)4]were determined to compare their structures, properties and catalytic activities. Both complexes have a tetrahedral geometry of MnSe4 or MnS4 core. An unusual difference (0.22 Å) between Mn–Se and Mn–S distances, and a large difference (0.22 Å) between Se–C and S–C were found, compared with those (0.11 Å and 0.15 Å, respectively) in (NMe4)2[MII(QPh)4] (M = Cd, Zn; Q = Se, S). The differences are ascribed to the stronger Mn–S π-bonding character than those of Cd–S, Zn–S and Fe–S.
Substituent Effects on the Formal Potential of the CoII/CoIII Redox Couple for Co(salen) Derivatives
Authors: Nishinaga Akira , Tajima Kunihiko , Speiser Bernd , Eichhorn Emerich , Rieker Anton , Ohya-Nishiguchi Hiroaki , Ishizu Kazuhiko 
Published: May 2006

Abstract
The formal potential of the CoII/CoIII redox couple in Co(salen) derivatives determined in DMF varies with the electronic as well as the steric properties of substituents at the aromatic rings in the salen ligand, where t-butyl groups shift the potential to more positive values, indicating strong steric interactions with solvent molecules.
Stereoselective Reduction of Enamino Sulfoxides
Authors: Ogura Katsuyuki , Tomori Hiroshi , Fujita Makoto 
Published: May 2006

Abstract
Enamino sulfoxides, p-TolS(O)CH=C(NR1R2)R (where R1 = alkyl, R2 = H or alkyl), were reduced with lithium tri(s-butyl)borohydride or borane·THF, respectively, to give β-amino sulfoxides of R*,R* configuration with high stereoselectivity.
Determination of Ethanol in Aqueous Solutions Using a Fiber-Optic Sensor with a Chitosan/Poly(vinyl alcohol) Cladding
Authors: Kurauchi Yoshiaki , Yanai Takayuki , Ohga Kazuya 
Published: May 2006

Abstract
Ethanol in aqueous solutions was determined by the use of an optical fiber with a cladding composed of chitosan and poly(vinyl alcohol). The response time of the probe for 50 v/v% ethanol was about 1 min and the relative standard deviation of the reproducibility was below 3% (n = 40).
Rearrangement of Allylic and Propargylic Alcohols Catalyzed by the Combined Use of Tetrabutylammonium Perrhenate(VII) and p-Toluenesulfonic Acid
Authors: Narasaka Koichi , Kusama Hiroyuki , Hayashi Yujiro 
Published: May 2006

Abstract
Allylic rearrangement and/or dehydration of allylic alcohols proceed by the use of a catalytic amount of tetrabutylammonium perrhenate and p-toluenesulfonic acid. Treatment of propargylic alcohols with the above reagents affords the rearranged products, α,β-unsaturated carbonyl compounds.
Thermolyses of Hexakis(trimethylsilyl)benzene and Pentakis(trimethylsilyl)toluene. The First Unique Trimethylsilyl-Triggered Rupture of Benzene Rings
Authors: Sekiguchi Akira , Ebata Keisuke , Terui Yoriko , Sakurai Hideki 
Published: May 2006

Abstract
Thermolysis of highly distorted hexakis(trimethylsilyl)benzene and pentakis(trimethylsilyl)toluene resulted in the formation of products arising from the ruptures of the aromatic rings.
Fluorination of Chlorinated Trifluoromethyl Ethers
Authors: Sekiya Akira , Ueda Kunimasa 
Published: May 2006

Abstract
Chlorine atoms in the chlorinated trifluoromethyl ether prepared from the reaction between chlorinated ethylenes and trifluoromethyl hypofluorite were fluorinated directly by fluorine gas. Tin(II) fluoride/sodium fluoride system was effective in the fluorination.
Synthesis of 2-Bis(trifluoromethyl)hydroxymethyl Substituted Cyclic Amines through Novel Intramolecular Substitution of an Arylsulfonyl Group
Authors: Taguchi Takeo , Suda Yoshimitsu , Hamochi Masahiko , Fujino Yasuhiro , Iitaka Yoichi 
Published: May 2006

Abstract
ω-Amino-1,1-bis(trifluoromethyl)-2-sulfonyl-1-pentanol or -hexanol provided the corresponding pyrrolidine or piperidine having BTHM group at the 2-position via intermediary epoxide by treating with NaOH in the presense of phase-transfer catalyst.
Synthesis and Characterization of Novel Tetranuclear and Binuclear Manganese(III) Complexes with 1,5-Bis(salicylideneamino)-3-pentanol
Authors: Mikuriya Masahiro , Yamato Yo , Tokii Tadashi 
Published: May 2006

Abstract
Tetranuclear and binuclear manganese(III) complexes with 1,5-bis(salicylideneamino)-3-pentanol (H3L), [Mn4(L)2(O)2(CH3COO)2]·4H2O·2CH3OH and [Mn2(L)(CH3O)(NCO)2(H2O)2], have been prepared and characterized by X-ray structure analysis and magnetic susceptibilities (80–300 K).
Pd-Catalyzed Regie- and Stereo-selective Carboxylation of Cycloalkanes with CO
Authors: Satoh Ko-ichi , Watanabe Jun , Takaki Ken , Fujiwara Yuzo 
Published: May 2006

Abstract
The reactions of cycloalkanes with CO via the C–H bond activation by Pd(OAc)2 catalyst have been found to proceed regio- and stereo-selectively to give corresponding carboxylic acids. The reactivity of C–H bonds of cycloalkanes decreases in the order: tert- &gt; sec- &gt; prim-carbon, and the stereochemistry of the substituents on the main products is all equatorial.