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1.
PLoS One ; 19(3): e0295031, 2024.
Article in English | MEDLINE | ID: mdl-38536835

ABSTRACT

Addressing soil nutrient degradation and global warming requires novel solutions. Enhanced weathering using crushed basalt rock is a promising dual-action strategy that can enhance soil health and sequester carbon dioxide. This study examines the short-term effects of basalt amendment on spring oat (Avena sativa L.) during the 2022 growing season in NE England. The experimental design consisted of four blocks with control and basalt-amended plots, and two cultivation types within each treatment, laid out in a split plot design. Basalt (18.86 tonnes ha-1) was incorporated into the soil during seeding. Tissue, grain and soil samples were collected for yield, nutrient, and pH analysis. Basalt amendment led to significantly higher yields, averaging 20.5% and 9.3% increases in direct drill and ploughed plots, respectively. Soil pH was significantly higher 256 days after rock application across cultivation types (direct drill: on average 6.47 vs. 6.76 and ploughed: on average 6.69 vs. 6.89, for control and basalt-amended plots, respectively), likely due to rapidly dissolving minerals in the applied basalt, such as calcite. Indications of growing season differences in soil pH are observed through direct measurement of lower manganese and iron uptake in plants grown on basalt-amended soil. Higher grain and tissue potassium, and tissue calcium uptake were observed in basalt-treated crops. Notably, no accumulation of potentially toxic elements (arsenic, cadmium, chromium, nickel) was detected in the grain, indicating that crops grown using this basaltic feedstock are safe for consumption. This study indicates that basalt amendments can improve agronomic performance in sandy clay-loam agricultural soil under temperate climate conditions. These findings offer valuable insights for producers in temperate regions who are considering using such amendments, demonstrating the potential for improved crop yields and environmental benefits while ensuring crop safety.


Subject(s)
Agriculture , Avena , Silicates , Seasons , Soil , Edible Grain , Crops, Agricultural
2.
Org Biomol Chem ; 21(24): 5033-5039, 2023 Jun 21.
Article in English | MEDLINE | ID: mdl-37264923

ABSTRACT

Two structurally diverse cyclic ß-hydroxy-α-nitrosulfones have been prepared and their isomerisation reactions studied. These cyclic ß-hydroxy-α-nitrosulfones undergo isomer equilibration via open-chain aldehyde forms under a variety of mild conditions. Michael condensation of 1,1'-[(1,3-dinitro-1,3-propanediyl)bis(sulfonyl)]bis(benzene) with propenal and subsequent cyclisation afforded 2,4-dinitro-2,4-bis(phenylsulfonyl)cyclohexanol in 98% yield as a mixture of four diastereomers. Sequential chromatography and recrystallization afford pure (1R,2R,4S)-rel-2,4-dinitro-2,4-bis(phenylsulfonyl)cyclohexanol based on spectroscopic and X-ray crystallographic data. This diastereomer equilibrates with the other three possible diastereomers under a variety of mild conditions: during silica gel chromatography, when dissolved in basic solution, and when dissolved in neutral polar solvents. Open-chain aldehyde forms are implicated as intermediates in isomer interconversion. Condensation of 1-methyl-4-[(nitromethyl)sulfonyl]benzene and pentanedial gives 2-(4-methylphenylsulfonyl)-2-nitrocyclohexane-1,3-diol as predominantly two diastereomers. Purification affords pure racemic diastereomer in 55% yield. This racemic diastereomer interconverts with several other isomers during silica gel chromatography. These isomers were identified as one, likely two, diastereomeric meso 2-(4-methylphenylsulfonyl)-2-nitrocyclohexane-1,3-diol isomers and four cyclic hemiacetal constitutional isomers. When dissolved in neutral polar solvents, the racemic diastereomer also interconverts with meso diastereomers and cyclic hemiacetals showing a marked solvent dependence. Reaction of the racemic diastereomer with triethylamine in dichloromethane results in isomerisation as well as substantial reversion to 1-methyl-4-[(nitromethyl)sulfonyl]benzene and pentanedial. Reaction with triethylamine in DMSO as well as simply warming in DMSO results in ring opening and concomitant dehydration to afford (E)-6-(4-methylphenylsulfonyl)-6-nitrohex-4-enal.

3.
Article in English | MEDLINE | ID: mdl-34341094

ABSTRACT

BACKGROUND AND OBJECTIVES: We sought to define the risk of severe coronavirus disease 2019 (COVID-19) infection requiring hospitalization in patients with CNS demyelinating diseases such as MS and the factors that increase the risk for severe infection to guide decisions regarding patient care during the COVID-19 pandemic. METHODS: A pilot cohort of 91 patients with confirmed or suspected COVID-19 infection from the Northeastern United States was analyzed to characterize patient risk factors and factors associated with an increased severity of COVID-19 infection. Univariate analysis of variance was performed using the Mann-Whitney U test or analysis of variance for continuous variables and the χ2 or Fisher exact test for nominal variables. Univariate and stepwise multivariate logistic regression identified clinical characteristics or symptoms associated with hospitalization. RESULTS: Our cohort demonstrated a 27.5% hospitalization rate and a 4.4% case fatality rate. Performance on Timed 25-Foot Walk before COVID-19 infection, age, number of comorbidities, and presenting symptoms of nausea/vomiting and neurologic symptoms (e.g., paresthesia or weakness) were independent risk factors for hospitalization, whereas headache predicted a milder course without hospitalization. An absolute lymphocyte count was lower in hospitalized patients during COVID-19 infection. Use of disease-modifying therapy did not increase the risk of hospitalization but was associated with an increased need for respiratory support. DISCUSSION: The case fatality and hospitalization rates in our cohort were similar to those found in MS and general population COVID-19 cohorts within the region. Hospitalization was associated with increased disability, age, and comorbidities but not disease-modifying therapy use.


Subject(s)
COVID-19 , Demyelinating Autoimmune Diseases, CNS , Hospitalization/statistics & numerical data , Immunologic Factors/therapeutic use , Registries/statistics & numerical data , Respiration, Artificial/statistics & numerical data , Adult , COVID-19/diagnosis , COVID-19/epidemiology , COVID-19/therapy , Cohort Studies , Comorbidity , Demyelinating Autoimmune Diseases, CNS/drug therapy , Demyelinating Autoimmune Diseases, CNS/epidemiology , Female , Humans , Immunologic Factors/adverse effects , Male , Middle Aged , Mortality , New England/epidemiology , Pilot Projects , Risk Factors , Severity of Illness Index
4.
Mult Scler Relat Disord ; 48: 102700, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33352355

ABSTRACT

BACKGROUND: In 2017, ocrelizumab became the first FDA approved disease modifying therapy (DMT) for primary progressive multiple sclerosis (MS). Although effective, adverse infusion-related reactions (IRR), such as erythema, pruritus, hives, and throat irritation, were frequently reported. OBJECTIVE: To develop an explanatory model of factors associated with increased odds of IRR development to further enhance clinical decision-making when administering ocrelizumab in a community setting. METHODS: A retrospective chart review was performed (n = 422) by extracting patient demographic factors and co-occurring conditions and symptoms from electronic medical records. Bivariate analyses were conducted to examine which demographic and clinical characteristics were associated with IRR development, and variables with a p-value of <.10 were then entered into a logistic regression to create the explanatory model. RESULTS: Being female (odds ratio [OR]: 2.60), Hispanic/Latinx (OR: 3.98), and having a history of a co-occurring tremor (OR: 3.78) were risk factors for increased odds of having an IRR. CONCLUSIONS: These findings may be helpful in guiding clinical practice routines and improving patient expectations regarding the likelihood of IRR development based on their individual demographics and co-occurring conditions and symptoms.


Subject(s)
Electronic Health Records , Immunologic Factors , Antibodies, Monoclonal, Humanized , Female , Humans , Retrospective Studies , Risk Factors
5.
Pharm Res ; 37(12): 234, 2020 Oct 29.
Article in English | MEDLINE | ID: mdl-33123783

ABSTRACT

PURPOSE: A multitude of different versions of the same medication with different inactive ingredients are currently available. It has not been quantified how this has evolved historically. Furthermore, it is unknown whether healthcare professionals consider the inactive ingredient portion when prescribing medications to patients. METHODS: We used data mining to track the number of available formulations for the same medication over time and correlate the number of available versions in 2019 to the number of manufacturers, the years since first approval, and the number of prescriptions. A focused survey among healthcare professionals was conducted to query their consideration of the inactive ingredient portion of a medication when writing prescriptions. RESULTS: The number of available versions of a single medication have dramatically increased in the last 40 years. The number of available, different versions of medications are largely determined by the number of manufacturers producing this medication. Healthcare providers commonly do not consider the inactive ingredient portion when prescribing a medication. CONCLUSIONS: A multitude of available versions of the same medications provides a potentially under-recognized opportunity to prescribe the most suitable formulation to a patient as a step towards personalized medicine and mitigate potential adverse events from inactive ingredients.


Subject(s)
Clinical Competence/statistics & numerical data , Drug Compounding/history , Pharmaceutic Aids/adverse effects , Prescription Drugs/chemistry , Drug Prescriptions , History, 20th Century , History, 21st Century , Humans , Pharmaceutic Aids/chemistry , Pharmaceutic Aids/history , Prescription Drugs/adverse effects , Prescription Drugs/history , Surveys and Questionnaires/statistics & numerical data
6.
Nature ; 583(7815): 242-248, 2020 07.
Article in English | MEDLINE | ID: mdl-32641817

ABSTRACT

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change1. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification2-4. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius5. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO2) per year with extraction costs of approximately US$80-180 per tonne of CO2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.


Subject(s)
Agriculture , Carbon Dioxide/isolation & purification , Crops, Agricultural , Geologic Sediments/chemistry , Global Warming/prevention & control , Goals , Silicates/chemistry , Atmosphere/chemistry , Brazil , China , Environmental Policy/economics , Environmental Policy/legislation & jurisprudence , Global Warming/economics , India , Iron/isolation & purification , Mining , Politics , Probability , Silicates/isolation & purification , Steel/isolation & purification , Temperature , Time Factors , United States
7.
Glob Chang Biol ; 26(6): 3658-3676, 2020 06.
Article in English | MEDLINE | ID: mdl-32314496

ABSTRACT

Land-based enhanced rock weathering (ERW) is a biogeochemical carbon dioxide removal (CDR) strategy aiming to accelerate natural geological processes of carbon sequestration through application of crushed silicate rocks, such as basalt, to croplands and forested landscapes. However, the efficacy of the approach when undertaken with basalt, and its potential co-benefits for agriculture, require experimental and field evaluation. Here we report that amending a UK clay-loam agricultural soil with a high loading (10 kg/m2 ) of relatively coarse-grained crushed basalt significantly increased the yield (21 ± 9.4%, SE) of the important C4 cereal Sorghum bicolor under controlled environmental conditions, without accumulation of potentially toxic trace elements in the seeds. Yield increases resulted from the basalt treatment after 120 days without P- and K-fertilizer addition. Shoot silicon concentrations also increased significantly (26 ± 5.4%, SE), with potential benefits for crop resistance to biotic and abiotic stress. Elemental budgets indicate substantial release of base cations important for inorganic carbon removal and their accumulation mainly in the soil exchangeable pools. Geochemical reactive transport modelling, constrained by elemental budgets, indicated CO2 sequestration rates of 2-4 t CO2 /ha, 1-5 years after a single application of basaltic rock dust, including via newly formed soil carbonate minerals whose long-term fate requires assessment through field trials. This represents an approximately fourfold increase in carbon capture compared to control plant-soil systems without basalt. Our results build support for ERW deployment as a CDR technique compatible with spreading basalt powder on acidic loamy soils common across millions of hectares of western European and North American agriculture.


Subject(s)
Soil , Sorghum , Agriculture , Carbon Dioxide , Dust , Edible Grain , Silicates
8.
Med Anthropol ; 38(8): 664-679, 2019.
Article in English | MEDLINE | ID: mdl-31017488

ABSTRACT

We compare the discourses on obesity found in early- and mid-twentieth century Mexican public discourse with those of Mexican geneticists and doctors today. We argue that postgenomic shifts towards non-determinism, apparently contained in current openness to epigenetics, need to be considered alongside the persistence of racialized genetic determinisms, and alongside the potential for epigenetic environmental determinisms. By exploring the environmentalist explanations of earlier eugenic thinking about obesity, we trace continuities in the gendered and racialized framings of obesity, which risk stigmatizing indigenous ancestry and attributing blame to individual mothers.


Subject(s)
Ethnicity/genetics , Eugenics/history , Obesity/genetics , Anthropology, Medical , Epigenesis, Genetic , Ethics, Medical , Female , Genetic Predisposition to Disease , History, 20th Century , Humans , Indigenous Peoples , Male , Mexico/ethnology , Sex Factors
9.
Chemosphere ; 227: 345-365, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30999175

ABSTRACT

The beneficial role of biochar on improvement of soil quality, C sequestration, and enhancing crop yield is widely reported. As such there is not much consolidated information available linking biochar modulated soil condition improvement and soil nutrient availability on crop yields. The present review paper addresses the above issues by compilation of world literature on biochar and a new dimension is introduced in this review by performing a meta-analysis of published data by using multivariate statistical analysis. Hence this review is a new in its kind and is useful to the broad spectrum of readers. Generally, alkalinity in biochar increases with increase in pyrolysis temperature and majority of the biochar is alkaline in nature except a few which are acidic. The N content in many biochar was reported to be more than 4% as well as less than 0.5%. Poultry litter biochar is a rich source of P (3.12%) and K (7.40%), while paper mill sludge biochar is higher in Ca content (31.1%) and swine solids biochar in Zn (49810 mg kg-1), and Fe (74800 mg kg-1) contents. The effect of biochar on enhancing soil pH was higher in Alfisol, Ferrosol and Acrisol. Soil application of biochar could on an average increase (78%), decrease (16%), or show no effect on crop yields under different soil types. Biochar produced at a lower pyrolysis temperature could deliver greater soil nutrient availabilities than that prepared at higher temperature. Principal component analysis (PCA) of available data shows an inverse relationship between [pyrolysis temperature and soil pH], and [biochar application rate and soil cation exchange capacity]. The PCA also suggests that the original soil properties and application rate strongly control crop yield stimulations via biochar amendments. Finally, biochar application shows net soil C gains while also serving for increased plant biomass production that strongly recommends biochar as a useful soil amendment. Therefore, the application of biochar to soils emerges as a 'win-win strategy' for sustainable waste management, climate change mitigation and food security.


Subject(s)
Charcoal/pharmacology , Nutrients/analysis , Soil/chemistry , Animals , Biomass , Charcoal/chemistry , Crops, Agricultural/drug effects , Crops, Agricultural/growth & development
10.
J Orthop Sports Phys Ther ; 46(10): 920-928, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27594662

ABSTRACT

Study Design Observational cohort. Background Outcomes for acute musculoskeletal injuries are currently suboptimal, with an estimated 10% to 50% of injured individuals reporting persistent problems. An early risk-targeted intervention may hold value for improving outcomes. Objectives To describe the development and preliminary concurrent and longitudinal validation of the Traumatic Injuries Distress Scale (TIDS), a new tool intended to provide the magnitude and nature of risk for persistent problems following acute musculoskeletal injuries. Methods Two hundred participants recruited from emergency medicine departments and rehabilitation clinics completed the TIDS and a battery of other self-reported questionnaires. A subcohort (n = 76) was followed at 1 week and at 12 weeks after the inciting event. Exploratory factor analysis and concurrent and longitudinal correlations were used to evaluate the ability of the TIDS to predict acute presentation and 12-week outcomes. Results Exploratory factor analysis revealed 3 factors explaining 62.8% of total scale variance. Concurrent and longitudinal associations with established clinical measures supported the nature of each subscale. Scores on the TIDS at baseline were significantly associated with variability in disability, pain intensity, satisfaction, anxiety, and depression at 12 weeks postinjury, with adequate accuracy to endorse its use as part of a broader screening protocol. Limitations to interpretation are discussed. Conclusion We present the initial psychometric properties of a new measure of acute posttraumatic distress following musculoskeletal injury. The subscales may be useful as stratification variables in subsequent investigations of clinical interventions. J Orthop Sports Phys Ther 2016;46(10):920-928. Epub 3 Sep 2016. doi:10.2519/jospt.2016.6594.


Subject(s)
Chronic Pain/diagnosis , Chronic Pain/psychology , Musculoskeletal System/injuries , Patient Reported Outcome Measures , Stress Disorders, Post-Traumatic/diagnosis , Trauma Severity Indices , Adolescent , Adult , Aged , Cross-Sectional Studies , Factor Analysis, Statistical , Female , Humans , Male , Middle Aged , Prognosis , Psychometrics , Reproducibility of Results , Risk Factors , Stress Disorders, Post-Traumatic/psychology , Young Adult
11.
Soc Stud Sci ; 45(6): 775-96, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27479996

ABSTRACT

The articles in this issue highlight contributions that studies of Latin America can make to wider debates about the effects of genomic science on public ideas about race and nation. We argue that current ideas about the power of genomics to transfigure and transform existing ways of thinking about human diversity are often overstated. If a range of social contexts are examined, the effects are uneven. Our data show that genomic knowledge can unsettle and reinforce ideas of nation and race; it can be both banal and highly politicized. In this introduction, we outline concepts of genetic knowledge in society; theories of genetics, nation and race; approaches to public understandings of science; and the Latin American contexts of transnational ideas of nation and race.


Subject(s)
Genomics , Racial Groups/psychology , Humans , Latin America
12.
Soc Stud Sci ; 45(6): 816-38, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27479998

ABSTRACT

This article analyses interrelations between genetic ancestry research, political conflict and social identity. It focuses on the debate on race-based affirmative action policies, which have been implemented in Brazil since the turn of the century. Genetic evidence of high levels of admixture in the Brazilian population has become a key element of arguments that question the validity of the category of race for the development of public policies. In response, members of Brazil's black movement have dismissed the relevance of genetics by arguing, first, that in Brazil race functions as a social--rather than a biological--category, and, second, that racial classification and discrimination in this country are based on appearance, rather than on genotype. This article highlights the importance of power relations and political interests in shaping public engagements with genetic research and their social consequences.


Subject(s)
Genetic Research , Politics , Racial Groups/classification , Self-Assessment , Social Identification , Brazil , Humans , Racial Groups/ethnology , Racial Groups/genetics , Social Discrimination/prevention & control
13.
Soc Stud Sci ; 45(6): 839-61, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27479999

ABSTRACT

This article explores the relationship between genetic research, nationalism and the construction of collective social identities in Latin America. It makes a comparative analysis of two research projects--the 'Genoma Mexicano' and the 'Homo Brasilis'--both of which sought to establish national and genetic profiles. Both have reproduced and strengthened the idea of their respective nations of focus, incorporating biological elements into debates on social identities. Also, both have placed the unifying figure of the mestizo/mestiço at the heart of national identity constructions, and in so doing have displaced alternative identity categories, such as those based on race. However, having been developed in different national contexts, these projects have had distinct scientific and social trajectories: in Mexico, the genomic mestizo is mobilized mainly in relation to health, while in Brazil the key arena is that of race. We show the importance of the nation as a frame for mobilizing genetic data in public policy debates, and demonstrate how race comes in and out of focus in different Latin American national contexts of genomic research, while never completely disappearing.


Subject(s)
Culture , Public Health , Public Policy , Racial Groups , Social Identification , Brazil , Genetic Research , Humans , Mexico
14.
Soc Stud Sci ; 45(6): 862-85, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27480000

ABSTRACT

Abstract This article examines the role that vernacular notions of racialized-regional difference play in the constitution and stabilization of DNA populations in Colombian forensic science, in what we frame as a process of public science. In public science, the imaginations of the scientific world and common-sense public knowledge are integral to the production and circulation of science itself. We explore the origins and circulation of a scientific object--'La Tabla', published in Paredes et al. and used in genetic forensic identification procedures--among genetic research institutes, forensic genetics laboratories and courtrooms in Bogotá. We unveil the double life of this central object of forensic genetics. On the one hand, La Tabla enjoys an indisputable public place in the processing of forensic genetic evidence in Colombia (paternity cases, identification of bodies, etc.). On the other hand, the relations it establishes between 'race', geography and genetics are questioned among population geneticists in Colombia. Although forensic technicians are aware of the disputes among population geneticists, they use and endorse the relations established between genetics, 'race' and geography because these fit with common-sense notions of visible bodily difference and the regionalization of race in the Colombian nation.


Subject(s)
Forensic Genetics , Colombia , DNA/analysis , Forensic Genetics/history , Forensic Genetics/legislation & jurisprudence , Forensic Genetics/standards , Genetic Research , History, 20th Century , History, 21st Century , Humans , Racial Groups
15.
Soc Stud Sci ; 45(6): 886-906, 2015 Dec.
Article in English | MEDLINE | ID: mdl-27480001

ABSTRACT

Using data from focus groups conducted in Colombia, we explore how educated lay audiences faced with scenarios about ancestry and genetics draw on widespread and dominant notions of nation, race and belonging in Colombia to ascribe ancestry to collectivities and to themselves as individuals. People from a life sciences background tend to deploy idioms of race and genetics more readily than people from a humanities and race-critical background. When they considered individuals, people tempered or domesticated the more mechanistic explanations about racialized physical appearance, ancestry and genetics that were apparent at the collective level. Ideas of the latency and manifestation of invisible traits were an aspect of this domestication. People ceded ultimate authority to genetic science, but deployed it to work alongside what they already knew. Notions of genetic essentialism co-exist with the strategic use of genetic ancestry in ways that both fix and unfix race. Our data indicate the importance of attending to the different epistemological stances through which people define authoritative knowledge and to the importance of distinguishing the scale of resolution at which the question of diversity is being posed.


Subject(s)
Attitude , Genetics, Population , Physical Appearance, Body , Racial Groups/psychology , Colombia , Focus Groups , Humans
16.
Beilstein J Org Chem ; 9: 2137-46, 2013.
Article in English | MEDLINE | ID: mdl-24204426

ABSTRACT

The tin(IV)-catalyzed reaction of ß-nitrostyrene with (E)-3-methyl-1,3-pentadiene in toluene afforded two major nitronic ester cycloadducts in 27% and 29% yield that arise from the reaction at the less substituted diene double bond. Also present were four cycloadducts from the reaction at the higher substituted diene double bond, two of which were the formal cycloadducts of (Z)-3-methyl-1,3-pentadiene. A Friedel-Crafts alkylation product from the reaction of the diene, ß-nitrostyrene, and toluene was also obtained in 10% yield. The tin(IV)-catalyzed reaction of ß-nitrostyrene with (Z)-3-methyl-1,3-pentadiene in dichloromethane afforded four nitronic ester cycloadducts all derived from the reaction at the higher substituted double bond. One cycloadduct was isolated in 45% yield and two others are formal adducts of the E-isomer of the diene. The product formation in these reactions is consistent with a stepwise mechanism involving a zwitterionic intermediate. The initially isolated nitronic ester cycloadducts underwent tin(IV)-catalyzed interconversion, presumably via zwitterion intermediates. Cycloadducts derived from the reaction at the less substituted double bond of (E)-3-methyl-1,3-pentadiene underwent a [3,3]-sigmatropic rearrangement on heating to afford 4-nitrocyclohexenes. Cycloadducts derived from the reaction at the higher substituted diene double bond of either diene failed to undergo a thermal rearrangement. Rates and success of the rearrangement are consistent with a concerted mechanism possessing a dipolar transition state. An initial assessment of substituent effects on the rearrangement process is presented.

17.
Chem Commun (Camb) ; (24): 3531-2, 2009 Jun 28.
Article in English | MEDLINE | ID: mdl-19521597

ABSTRACT

O-Allyl nitronic esters that are obtained from tin(IV) catalyzed Diels-Alder reactions undergo thermal rearrangement to gamma,delta-unsaturated nitro compounds.

18.
Conn Med ; 72(9): 525-6, 2008 Oct.
Article in English | MEDLINE | ID: mdl-18833868

ABSTRACT

Pinealgland tumors comprise 0.5%-1% of adult brain tumors. Pineoblastomas constitute less than half of these pineal gland tumors. Due to the key anatomic location, these tumors produce hydrocephalus by pressing on the aqueduct of Sylvius. Headache is a very common symptom. We describe the case of a 20-year-old female who presented with new onset persistent headache. Workup revealed a pineoblastoma. These tumors can be detected by MRI and diagnosed on cytology of cerebrospinal fluid (CSF) showing blue round tumor cells with specific tumormarkers. Combined chemo radiation therapy is the treatment for these tumors. New onset persistent headaches are present in 50%-60% of intracranial tumors. All new onset persistent headaches should be promptly evaluated.


Subject(s)
Headache/etiology , Pinealoma/pathology , Adult , Female , Humans , Pinealoma/diagnosis , Pinealoma/therapy
19.
Chem Commun (Camb) ; (10): 1090-1, 2002 May 21.
Article in English | MEDLINE | ID: mdl-12122679

ABSTRACT

Diels-Alder reaction of nitroethylene derivatives with cyclohexa-1,3-diene afforded three pericyclic products some of which could be converted to others via a new [3,3]-sigmatropic rearrangement or via a Claisen rearrangement.

20.
J Org Chem ; 67(9): 2859-63, 2002 May 03.
Article in English | MEDLINE | ID: mdl-11975538

ABSTRACT

Racemic N-methyl-S-(nitromethyl)-S-phenylsulfoximine (2) was prepared in 87% yield via alkaline nitration of N,S-dimethyl-S-phenylsulfoximine. Optically active N-methyl-S-(nitromethyl)-S-phenylsulfoximine (both enantiomers) was prepared in similar fashion. Reaction of racemic 2 with p-chlorophenyl isocyanate and a catalytic quantity of triethylamine in the presence of furan afforded dihydrofuroisoxazole 5, the product of nitrile oxide cycloaddition, in 42% yield (65:35 diastereomer ratio). Reaction of the dihydrofuroisoxazole 5 with phenyllithium and methyllithium afforded replacement of the sulfoximine group by phenyl and methyl, respectively. Reaction of racemic 2 with aromatic isocyanates and potassium carbonate afforded C-acylation products in 70-78% yield which existed as the ylide tautomers 9a,b. Methylation of racemic 2 afforded the C-alkylate N-methyl-S-(1-nitroethyl)-S-phenylsulfoximine (13), existing as the neutral tautomer.

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