Biochar as a sustainable alternative to carbon black in agricultural mulch films.

Examples of biochar as an alternative to traditional plastic fillers, like carbon black, are numerous and growing. However, in the agricultural mulch film application, both the polymer and its fillers are pushed to their mechanical limit to obtain an effective product, using the least amount of plastic. Through a combined techno-economic analysis (TEA) and life cycle assessment (LCA), this study characterizes the use of carbon-negative biochar as an opacity filler in mulch film applications. Due to its larger particle size, the biochar demands additional thickness to achieve equivalent opacity as carbon black in films. A thicker film translates to additional polymer demand, and a significant increase in price and environmental impact. A comparable formulation for an equal price ($623 per mulched ha) as a 2.6 wt % carbon black with 25 µm thickness was derived, needing 15 wt % biochar and a thickness of 30 µm. The biochar formulation resulted in a slightly higher global warming potential (3% increase), but much larger impact in the land use category (+339%), and the sample was deemed not fit for use in the intended mulch application. These results indicate that in applications where the polymeric matrix and its fillers are pushed to their mechanical limit, the displacement of traditional fillers by biochar is challenging. However, biochar derived from waste biomass (thus reducing land use impact) remains a valid, environmentally beneficial solution to displace traditional fillers for non-extreme plastic uses (commodity plastics) and thicker composites.

Prevalence and pathogenicity of Clostridium difficile in hospitalized patients. A French multicenter study.

BACKGROUND: Although Clostridium difficile is the main agent responsible for nosocomial diarrhea in adults, its prevalence in stool cultures sent to hospital microbiology laboratories is not clearly established. OBJECTIVES: To determine the prevalence of C difficile in inpatient stools sent to hospital microbiology laboratories and to assess the relationship between serotypes and toxigenicity of the strains isolated and the clinical data. METHODS: From January 18, 1993, to July 31, 1993, the presence of C difficile was systematically investigated in a case-control study on 3921 stool samples sent for stool culture to 11 French hospital microbiology laboratories. The prevalence of C difficile in this population (cases) was compared with that of a group of 229 random hospital controls matched for age, department, and length of stay (controls). Stool culture from controls was requested by the laboratory although not prescribed by the clinical staff. Serotype and toxigenesis of the strains isolated were compared. RESULTS: The overall prevalence of C difficile in the cases was twice the prevalence in the controls (9.7% vs 4.8%; P < .001) and was approximately 4 times as high in diarrheal stools (ie, soft or liquid) as in normally formed stools from controls (11.5% vs 3.3%; P < .001). The strains isolated from diarrheal stools were more frequently toxigenic than those isolated from normally formed stools. Serogroup D was never toxigenic, and its proportion was statistically greater in the controls than in the cases (45% vs 18%; chi 2 = 5.2; P < .05). Conversely, serogroup C was isolated only from the cases. Clostridium difficile was mainly found in older patients ( > 65 years), suffering from a severe disabling disease, who had been treated with antibiotics and hospitalized for more than 1 week in long-stay wards or in intensive care. CONCLUSIONS: This multicenter period prevalence study clearly supports the hypothesis of a common role of C difficile in infectious diarrhea in hospitalized patients. Disease associated with C difficile should therefore be systematically evaluated in diarrheal stools from inpatients.

Rey-Martinez Kangaroo Mother Program: an alternative way of caring for low birth weight infants? One year mortality in a two cohort study.

OBJECTIVES: To assess the effectiveness and safety of the Kangaroo mother intervention (KMI). DESIGN: Observational, analytic, prospective (two cohorts) study. SETTING: Two large tertiary care obstetric hospitals, one offering "traditional" care and the other KMI. PATIENTS: Newborn infants with birth weights < or = 2000 g, who survive the neonatal period and are eligible for an in-patient minimal care unit (MCU) (having overcome major adaptation problems to extra uterine life). INTERVENTIONS: "Kangaroo infants" (KI) were discharged as soon as they were eligible for MCU, regardless of weight or gestational age. Infants were kept 24 hours a day in an upright position, in skin-to-skin contact and firmly attached to the mother's chest until the KMI was not tolerated anymore. Control babies (from the other facility) were kept in incubators at the MCU until they satisfied usual discharge criteria for the control hospital. Both groups were followed periodically up to the age of 1 year. RESULTS: Three hundred thirty-two eligible infants were recruited, 162 at the Kangaroo hospital and 170 at the control hospital. KI came from a much lower socio-economic class and were more ill before eligibility. Relative risk of death was higher for KI (RR 1.9), although this figure was reversed after adjusting for weight at birth and gestational age (RR 0.5). KI grew less in the first 3 months and had a higher proportion of developmental delay at 1 year, and a multivariate analysis failed to control for the large baseline differences in socioeconomic levels and babies' health status between the two cohorts. CONCLUSIONS: In spite of major baseline differences between studied cohorts, the survival of LBW infants in Bogotá is similar between the KMI and the "traditional care". Questions remain about quality of life, especially regarding weight gain and neurodevelopment, that may be answered by a Randomized Controlled Trial.

[Computer simulation of the 10-year outcome of a cohort of heroin addicts in Ile-de-France]. / Simulation informatique du devenir à 10 ans d'une cohorte d'héroïnomanes en Ile-de-France.

The aim of this study is to develop a computer simulation model to describe imaginary cohorts of heroin users in the Ile de France (greater Paris) region. Because of the lack of well-designed cohort studies in France, this model is based on epidemiological data found in various different studies. The results of the simulation reveal horrifying outcomes in ten years' time: in the more optimistic scenario (an annual non-Aids mortality rate of 1%, an annual rate of permanent addiction curtailment of 10% and a syringe exchange rate of 10%), only 50% of heroin users curtail their consumption permanently without being HIV carriers after 10 years, 16% are HIV carriers and 10% have died. In conclusion, medical care should play an important part in the management of drug users, and secondary prevention aimed at reducing the health problems involved in heroin use should be intensified.

[Management of drug addicts (heroin addicts) by general practitioners]. / La prise en charge des toxicomanes (héroïnomanes) par les médicins généralistes.

A telephone survey has been undertaken in a random sample of 150 General Practitioners (GPs) in four regions of France. 25% refused to answer. The study showed that drug addiction (use of heroin) is a serious issue for many of these physicians: 15% follow more than 20 drug addicts per year and only 12% see none; extrapolating the mean number of drug addicts followed yearly (9.4 per GP) to all GPs in the four regions (26,000, that is to say half of all french GPs) give an "active file" of 250,000 drugs addicts per year. Only 15% if the GPs feel they are educated for the management of drug addicts, although 70% say they prescribe medication such as hypnotics and anxiolytics (97%), the most cited being Tranxene 50 (Chlorazepate 50 mg), antalgics (84%), morphinic or morphine-like drugs (49%), mainly Temgesic, and at last antidepressants and neuroleptics (39%). GPs suffer from being isolated in their practices, as contacts with collegues or institutions specialized in drug addiction are few. If one third of the GPs wish an active participation in the management of drug addicts, and one third wish at least to "do something", they are all much ambiguous in their attitudes toward drug addiction. Their behaviors vary from medical pride to anxiety and even fear. They all mention a lot of practical problems with respect to reputation, practice, lack of time... Unanimous wishes concern opportuneness of setting up continuous medical education on this topic, of working out guidelines for prescription, of improving relationships with other institutions.

[Two years follow-up of a heroin users cohort treated with high dosage buprenorphine. Results of the SPESUB study (pharmacoepidemiologic follow-up of general practice Subutex)]. / Suivi à 2 ans d'une cohorte de patients sous buprénorphine haut dosage. Résultats de l'étude SPESUB (suivi pharmaco-épidémiologique du Subutex en médecine de ville).

BACKGROUND: Since February 1996, French GPs are allowed to prescribe high dosage buprenorphine for maintenance treatment of major opioid drug addiction. A prospective cohort of major opioid addicts was initiated in order to assess patient outcomes: follow-up, retention rate in treatment, drug use, intravenous injection and social situation evolution. METHODS: Each GP, known to be involved in drug user management, had to include the first 10 opioid drug addict patients to whom he prescribed high dosage buprenorphine, with a maximum inclusion period of 3 months. Patients were followed up for two years and a regular standardized information was collected (usual data on drug users and prescription modalities). RESULTS: Between May and July 1996, 919 patients (664 men and 255 women, mean age: 30 years) were included by 101 GPs. They had a long and serious history of drug addiction, important parallel consumption of cocaine, codeine and other illicit drugs and psychiatric problems (28% of definite problems and 45% of probable) and frequent hepatic conditions (hepatitis B: 23%, hepatitis C: 21%). Two years later, 55% of patients were still followed-up by the same GP and an additional 12% were followed by another GP or in a health care service (hospitalized or receiving methadone in a specialized centre). 13% were not followed, but GPs were able to describe their situation. 8% had been included by GPs who had dropped the study. Finally, 12% of patients were lost to follow-up. Among the 508 patients still followed-up by the same GP after 2 years, the substitution treatment rate was 84%. The dosage bracket had widened (inclusion: mean dosage=7.8 mg +/-4.5, minimum=0.8, maximum=28, median=8; after 2 years: mean=7.6 mg +/-5.4, minimum=0.4, maximum=28, median=8) and the duration of the prescription and dispensing had increased. Declaration of heroin intake in the previous month had fell from 40% to 11% and declaration of drug intake from 53% to 20%. Social situation had improved on average (housing conditions and work). There were 12 seroconversions for hepatitis B, 21 for hepatitis C and 4 for HIV. 14% of patients had declared intravenous injection of high dosage buprenorphine in the previous month. CONCLUSION: After two years of follow-up, 55% of patients were still followed-up by the same GP and an additional 12% was followed by another GP or in a health care service. Among patients still followed up by the same GP, a reduction of drug related harm (seroconversions for hepatitis B, hepatitis C and HIV) was observed.

[4-month follow-up of 198 heroin addicts by general practitioners]. / Suivi à 4 mois de 198 héroïnomanes par des médecins généralistes.

This study aimed to describe the short term follow-up of a cohort of 198 i.v. heroin users by 44 highly motivated General Practitioners (GPs). The study showed that for these GPs, the work-load linked with the care of these patients was heavy. Nearly half of them saw at least one drug-addict every day. These GPs work within a network and stated they benefit from a regular training on drug addiction topics. The profile of i.v. heroin users, followed by these GPs, is different from the ones usually described in other health care structures (higher percentage of women and better social insertion). The two main motives to consult a GP are the demand of drugs concerning their addiction and medical concern (due to infectious diseases especially). The answer of GPs, concerning the demand of drugs, divide physicians into two groups: those who never prescribe morphine like drugs as substitution and those who do so. In addition, both of them often prescribe psychotropic drugs to some of their patients. Nevertheless, these prescriptions are just one of the elements of a follow-up contract between a GP and his patients. Morphine like prescription is more frequently described among long term drug-addicts already well-known by GPs. This selection prohibits a straight comparison of the results of two groups of patients (with and without morphine like substitution). But the main fact is that patients under morphine like substitution are followed better (in terms of continuity) after 4 months of observation.

[Dependence, abuse and misuse of drugs: knowledge and attitudes of private physicians in the Ile-de-France]. / Dépendance, cumul, abus et détournement de médicaments: connaissances et attitudes des médecins libéraux d'Ile-de-France.

BACKGROUND: The rise in drug consumption and poorly adapted prescription practices are currently a growing problem. In the face of this trend, "L'Union Professionnelle des Médecins Libéraux d'Ile-de-France" investigated the awareness and the attitude of physicians towards drug dependency, abuse and misuse. METHODS: One hundred physicians and 50 specialists, randomly selected, were contacted by phone. They were asked to give their own description of dependency, abuse and misuse based on patients' attitudes. They were to describe cases of their patients classifying them according to each category. In the second part of the phone interview, the physicians were to give their view about existing and potential tools to solve these problems. RESULTS: Dependency, abuse and misuse problems were well known and frequent: 94% of physicians have such experience and among those, 60% saw such a patient more than once a week. The population concerned by these problems were generally middle-aged women with chronic disease. Misuse behavior was less easily identified (53% of the physicians described such patients). They generally concerned young men, most often drug addicts. From a global point of view, psychotropes were the most frequently misuse drugs, followed by the pain drugs and nsaids. These types of drugs are used routinely, some of them being sold without prescription. Diseases concerned were essentially psychiatric disorders, sleeping troubles and long lasting pains well classified. To face these problem, physicians recommend a dialogue between medical members and patients as well as a changing in professional (physicians and pharmacists) behavior such as firmness, education and listening. CONCLUSION: Situations evoked during the survey were frequent but non systematically discerned as damageable. As a matter of fact, these observations are only a piece of an "intuitive" estimation of the risk versus benefit of the prescription of the drugs mentioned above. Actual regulation and control tools seem to be somewhat irrelevant to solve the problem.

[Effects of an educational campaign on cardiovascular risk factors in a French town (Epernon, study town). Methods and preliminary results: prevalence and level of risk factors]. / Influence d'une campagne d'information sur les facteurs de risque cardiovasculaire dans une ville française (Epernon, Ville d'Etude). Méthodologie et résultats préliminaires: prévalence et niveau des facteurs de risque.

The authors report the methods and preliminary findings of a study scheduled to last 5 years, which aims to evaluate cardiovascular risk factor changes in response to an education program. The population sample consisted of 961 subjects, from Epernon itself (the study town) and from two control towns. The assessment criteria were reported at the beginning of the study and then again after 2 and 5 years. They consisted of an analysis of medical events and of biomedical and dietary data and a detailed analysis of behavior with regard to health and socio-economic variables. Preliminary data show that the samples were similar in Epernon and the control towns and also comparable to some French epidemiological data. There is a striking difference between the percentage of subjects aware of their blood pressure (65.5%) and blood cholesterol (13.4%) levels.