Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “work intensity”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,063 records · Page 59Linked to original sources
PubMed1986

Analysis of shear-induced platelet aggregation with population balance mathematics.

Suspensions of blood platelets aggregate and degranulate when subjected to a shearing flow of sufficient intensity. This work examines, by means of a population balance technique, the kinetics of platelet aggregation in a shear field. The particle collision efficiency, epsilon, and the particle void volume fraction, phi, are estimated from particle number density data. The collision efficiency represents the fraction of particle collisions that result in the binding together of the involved particles. We term epsilon and phi population balance properties because they refer to physical characteristics of platelets and aggregates that are pertinent to their aggregation behavior. Experiments focused on the dependence of epsilon on platelet concentration, shearing rate, and time in a controlled shear field. The collision efficiency is lower in dilute platelet suspensions. This finding supports an ADP-mediated mechanism for shear aggregation. The collision efficiency passes through a maximum with respect to shearing rate, suggesting a competition between the opposing effects of increasing platelet activation and increasing collision violence. The collision efficiency is highest during the first ten seconds in the shear field and declines significantly thereafter. Even at its maximum, however, epsilon for shear aggregation is small: only about one in every thousand particle collisions results in binding.

Adult↗
PubMed1996

HIV-1 infection kinetics in tissue cultures.

Despite intensive experimental work on HIV-1, very little theoretical work has focused on HIV-1 spread in tissue culture. This article uses two systems of ordinary differential equations to model two modes of viral spread, cell-free virus and cell-to-cell contact. The two models produce remarkably similar qualitative results. Simulations using realistic parameter regimes showed that starting with a small fraction of cells infected, both cell-free viral spread and direct cell-to-cell transmission give an initial exponential phase of viral growth, followed by either a crash or a gradual decline, extinguishing the culture. Under some conditions, an oscillatory phase may precede the extinction. Some previous models of in vivo HIV-1 infection oscillate, but only in unrealistic parameter regimes. Experimental tissue infections sometimes display several sequential cycles of oscillation, however, so our models can at least mimic them qualitatively. Significantly, the models show that infective oscillations can be explained by infection dynamics; biological heterogeneity is not required. The models also display proportionality between infected cells and cell-free virus, which is reassuringly consistent with assumptions about the equivalence of several measures of viral load, except that the proportionality requires a relatively constant total cell concentration. Tissue culture parameter values can be determined from accurate, controlled experiments. Therefore, if verified, our models should make interpreting experimental data and extrapolating it to in vivo conditions sharper and more reliable.

CD4-Positive T-Lymphocytes↗
PubMedDate not supplied

Unstable malaria in Sudan: the influence of the dry season. Malaria in areas of unstable and seasonal transmission. Lessons from Daraweesh.

Most studies of the natural history of Plasmodium falciparum infection have been performed in areas of stable malaria transmission and the acquisition of immunity to malaria in individuals who live in such areas is well documented. For the past 10 years, we have monitored host-parasite relationships in an area characterized by unstable and seasonal malaria of low transmission intensity. The work was performed in the village Daraweesh located in north-eastern Sudan 16 km from Gedaref town. The climate of the region is characterized by well-defined wet and dry periods with a short rainy season followed by a long dry season. In some years the rains fail and there is little precipitation even during the wet season. Malaria cases are rare in the dry season and during droughts. In years with rains, falciparum malaria sweeps through Daraweesh during the wet season and 20-40% of the entire population suffer at least 1 attack of malaria. All age-groups are affected, but the risk of getting a clinical attack is about twice as high in the age-group from 5 to 20 years as in adults aged above 30 years. Serological data and evidence obtained by polymerase chain reaction indicate that only about half of new blood-stage infections cause clinical disease. Together these findings suggest that many new infections are controlled immunologically and that individuals aged over 30 years are more successful in controlling infections than are teenagers. Parasite strains collected in Daraweesh are genotypically diverse and it is likely that the outcome of new P. falciparum infections depends on the preparedness of the host immune system to mount an attack against polymorphic or variable antigens expressed by the infecting parasite.

Adolescent↗
PubMed2002

Exposure to polybrominated diphenyl ethers and tetrabromobisphenol A among computer technicians.

This study investigates exposure to polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA), which are used as flame retardants in electronic equipment, in a group of technicians with intense computer work. Thirteen PBDE congeners and TBBPA were quantified in serum from 19 computer technicians. Previously investigated groups of hospital cleaners with no computer experience, and clerks working full-time at computer screens were used for comparison. The computer technicians had serum concentrations of BDE-153, BDE-183 and BDE-209 that were five times higher than those reported among hospital cleaners and computer clerks. The median levels observed among the computer technicians were 4.1, 1.3, and 1.6 pmol/g lipid weight, respectively. In contrast, for BDE-47 there was no difference between the computer technicians and the others. BDE-100, BDE-203, and three structurally unidentified octa-BDEs and three nona-BDEs, were present in almost all samples from the computer technicians. Further, TBBPA was detected in 8 out of 10 samples. The levels of BDE-153, BDE-183, and one of the octa-BDEs were positively correlated with duration of computer work among technicians. On a group level an exposure gradient was observed, from the least exposed cleaners to the clerks, and to the highest exposed group of computer technicians. A dose (duration of computer work)-response relationship among computer technicians was demonstrated for some higher brominated PBDE congeners. Thus, it is evident that PBDEs used in computers and electronics, including the fully brominated BDE-209, contaminate the work environment and accumulate in the workers tissues.

Adult↗
PubMed1975

Ill-health and child abuse.

Intensive therapeutic work with families, in which child abuse had occurred, suggested that bonding failure related in part to the pregnancy, perinatal experience, and early ill-health of the abused proband and parents. 25 consecutive unequivocally abused children who had 1 or more siblings were selected from our referrals. Six factors emerged as highly significantly over-represented in the proband biography as compared with the control sibling group: abnormal pregnancy, abnormal labour or delivery, neonatal separation, other separation in the first six months, illnesses in the first year of life, and illness in the mother in first year of life. These data suggest that treatment of parents during pregnancy the perinatal period, and early infancy may well be fruitful in the prevention of child abuse.

Adolescent↗
PubMed1997

Phagocytosis of chemically modified carbon materials.

An oxidizing treatment of carbon fibres in boiling nitric acid leads to significant changes in the chemical state of their surface. As a result of the chemical treatment on a hydrophobic carbon surface, hydrophilic domains are formed and phenolic, carbonyl and carboxyl groups appear. In this work the intensity of phagocytosis of carbon fibres obtained by carbonization of polyacrylonitrile was studied both for HNO3 etched and non-etched fibres. Part of the powdered material studied was placed in plasma before it was contacted with cells. To study the material, which was first placed in plasma and then contacted with cells, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used. It was found that the powders made from the etched fibres are phagocytized more intensively. It was also found that the absorption of plasma proteins enhances the phagocytosis only for the fibres oxidized in HNO3 and has no influence in the case of powders obtained from non-etched fibres.

Animals↗
PubMedDate not supplied

Reducing resource consumption through work redesign in a surgical intensive care unit: a multidisciplinary, protocol-based Progressive Care Area.

Patients with prolonged intensive care unit (ICU) length of stay, though few in number, consume as much as 50% of ICU resources. With increasing pressures for cost containment in health care, the availability of ICU beds may be jeopardized. To improve the efficiency of care for patients requiring a surgical intensive care unit (SICU) stay of 3 or more days, a multidisciplinary, highly "protocolized," Progressive Care Area was developed within the existing SICU environment. Entry into this area is limited to patients whose acuity level is not high by ICU standards, but too high for a general surgical floor. In designing the Progressive Care Area, we drew on a number of published management strategies-including total quality management concepts and our prior experience in establishing ventilator management teams. The Progressive Care Area has resulted in a reduction in both the frequency and variation of resources used. A Progressive Care Area within an existing ICU is a viable alternative for the care of the patients who have prolonged lengths of stay and are less acutely ill, and it significantly improves ICU efficiency.

Data Collection↗
PubMed2003

Service production and contract choice in primary physician services.

Since payment systems for physicians may affect the efficiency of health care service provision, the design of compensation schemes is a major policy concern. According to standard labour economics and agency theory, fee-for-service contracts are likely to induce higher service production than salary contracts and (pure) capitation contracts. Payment systems may also influence service quality and the overall cost control. Despite the obvious policy significance of these issues, the available empirical research is very limited. This paper is an attempt to remedy this situation by addressing the impact of alternative contracts and payment systems on primary care physicians' service supply. The Norwegian primary physician service is an ideal setting for exploring the impact of payment systems. It is a centralised scheme where health services are mostly publicly financed. Until the June 1st 2001, there were two main types of primary care physicians: local government employees remunerated by a fixed salary, and contract physicians mostly financed by fee-for-service payments. We find that physicians with a fee-for-service contract produce a higher number of consultations and other patient contacts than physicians with a fixed salary. This difference is mostly due to longer working hours, but time efficiency is greater as well. Moreover, a part of the difference is due to a selection effect: salaried physicians prefer shorter working hours and prefer to work less intensively. When these and other effects are taken into account, we find that a change from a salary contract to a fee-for-service contract will increase service production by 20-40%.

Capitation Fee↗
PubMed1996

Histories of childhood trauma and complex post-traumatic sequelae in women with eating disorders.

The profound self-destructiveness and tenacity of eating disorders found among women abused and neglected in childhood become comprehensible when understood within a complex posttraumatic conceptualization as desperate attempts to regulate overwhelming affective states and construct a coherent sense of self and system of meaning. Trauma leads to the predictable consequences of dysregulation of the arousal system, avoidance, and constriction of affect; coherence of self and world are shattered. Abused patients' childhood experiences teach them that to need is to expose oneself to the pain of abandonment and betrayal at the hands of individuals responsible for their care. Consequently, needs-psychological, physical, and spiritual-come to be perceived as dangerous, and human relationships are simultaneously yearned for and feared. Robbed of the opportunity to develop a cohesive self and a coherent system of meaning and faith to sustain from within, the traumatized eating-disorder patient turns to the culture to tell her who to be and how to live; she learns that to conquer rather than satisfy needs and to be "in control" (an internal state of equanimity manifested externally in a thin body) will bring meaning and purpose. Binge eating, purging, and starving become apt metaphors for the boundless hunger, the wish to fulfill needs together with the wish to rid oneself forever of need, the desire to "purify" the damaged psychic and physical self, and the hope of restoring meaning. The treatment of the traumatized eating disorder patient is complex. Individual therapy provides the opportunity for intensive relational work that begins to restore faith in human connection and that provides a "safe base" from which to examine the trauma and separate past from present. Therapy groups for eating-disordered women and trauma survivors provide relief from isolation, valuable perspectives from others who have "been there," and the opportunity to contribute to others' healing as one heals. Ultimately, these patients must be willing to leave the world of obsession with food and weight, which guarantees safety from interpersonal hurt while it simultaneously guarantees that hope will not be restored. Though reconnecting with humanity carries the risk of further pain, it opens up the opportunity for connection, healing, and growth.

Feeding and Eating Disorders↗
PubMed2003

Emotion induction moderates effects of anger management style on acute pain sensitivity.

Anger management style (AMS) is related to both acute and chronic pain intensity. Recent work suggests that an anger expressive AMS in particular may influence acute pain, and that this effect may be most pronounced during anger provocation. The present study examined whether AMS was related to subsequent pain sensitivity without regard to prior emotion induction, only when a strong negative emotion was evoked, or only when anger was provoked. Sixty-four healthy normals partook in semi-structured interviews in which they recalled and verbally described an event in which either anger, sadness, or joy was elicited. They then underwent a cold pressor pain task. Results of hierarchical multiple regressions showed that an anger expressive AMS was related positively to pain threshold only for participants in the anger-recall condition, and that this effect was largely accounted for by their low SBP reactivity during emotion induction. An anger suppressive AMS was related positively to increases in self-reported pain severity, irrespective of emotion-induction condition, and this effect was not accounted for by reactivity in any cardiovascular index. Results extend those of previous studies by illuminating the potential importance of behavioral anger expression for individuals prone to express anger in modulating their reactivity and pain sensitivity. Findings suggest that the detrimental effects of an anger expressive style on pain sensitivity may be ameliorated under conditions in which behavioral anger expression occurs. Results are discussed in terms of recent work suggesting that an expressive AMS is associated with endogenous opioid dysfunction in the absence of behavioral anger expression.

Acute Disease↗
PubMed2003

Are nurses prepared to manage cancer pain? A national survey of nurses' knowledge about pain control in Taiwan.

Nurses play a crucial role in cancer pain control, but little is known about how well-prepared nurses are to manage cancer pain in Taiwan. The purpose of this study was to examine the level of knowledge about pain management among Taiwanese nurses with different background characteristics and to determine the predictor(s) of nurses' pain management knowledge. Nurse subjects were recruited by a cross-sectional nationwide survey with stratified sampling from nine hospitals distributed in the four major geographic regions of Taiwan. The Nurses' Knowledge and Attitudes Survey-Taiwanese version (NKAS-T) and a background information form were used to collect the data. Of 1900 surveys distributed, 1797 valid questionnaires (94.5%) were analyzed. The average correct response rate was 50.5%, with rates ranging from 7-86% for each survey question. Results from stepwise regression showed that nurses with higher mean correct answer scores had BS or higher degrees, had received pain education at professional conferences, had more prior hours of pain education, had longer clinical care experiences, and always worked with cancer patients. Nurses who worked in intensive care units, however, had significantly lower mean correct scores. The results strongly suggest an urgent need to strengthen pain education in Taiwan. The results also provide the direction for developing pain education.

Data Collection↗
PubMed1999

Estimation of flavin-containing monooxygenase activity in intact hepatocyte monolayers of rat, hamster, rabbit, dog and human by using N-oxidation of benzydamine.

The flavin-containing monooxygenase (FMO)-dependent N-oxidation of benzydamine has been assessed as a method for monitoring the activity of FMOs in monolayer cultures of hepatocytes from rat, dog, rabbit, hamster and human. The advantage of this substrate is that benzydamine N-oxide formation can be measured directly in extracts of cellular incubations without an intensive work-up procedure. Benzydamine and its N-oxide are readily separated by HPLC with fluorometric detection. This assay proved sensitive enough to monitor FMOs activity in intact monolayer of cultured hepatocytes. The formation of benzydamine N-oxide was inhibited when hepatocytes were coincubated with methimazole (another FMO substrate) in a dose-dependent manner, whereas N-octylamine (an inhibitor of cytochrome P450) had no inhibitory effect. In contrast to cytochrome P450, FMO activity assessed by benzydamine N-oxidation was relatively stable for all species studied during 72-h cultures.

Animals↗
PubMed1993

Long-term outcome of infants born preterm.

This chapter outlines some of the many long-term health problems to be expected in surviving preterm children. They have higher rates of sensorineural impairments (such as cerebral palsy, and visual, auditory and intellectual impairments) and sensorineural disabilities from these impairments, than children born at term. In addition, they grow poorly and have higher rates of other health problems, including poorer respiratory health in early childhood. There is little doubt that preterm children contribute disproportionately to the prevalence of health problems in childhood. However, there are still many gaps in our knowledge of the outcome for preterm survivors, particularly regarding outcome in adulthood. Obstetricians and neonatologists working in intensive care, as well as parents, want to know the long-term outcome for preterm children born today, not that of children born a generation ago when fewer preterm children (particularly those of extremely low birthweight) survived. Despite the many problems, the conclusion is that most preterm children are as healthy as term children, suffering only usual childhood illnesses; we feel confident that the majority make, and will continue to make, useful contributions to their families and the societies in which they live.

Cohort Studies↗
PubMed1995

Auditing quality of nursing care.

Nurses working in intensive therapy units (ITU) may perceive that they provide a good quality of nursing care to patients and relatives in the ITU. But how can this be assessed, to enable nurses to have an indication of the actual quality of nursing care? This article examines quality and audit within nursing, and then examines one of the commercially produced tools that can be utilised to give an indication of the nursing care provided within the ITU. The results of a part pilot study are imparted and then further discussed. ITU nurses need to be aware that if they do not commence auditing their nursing care then someone with no specialist knowledge may dictate to them what to do to audit their care.

Attitude of Health Personnel↗
PubMed1995

Preventing the ITU syndrome or how not to torture an ITU patient! Part I.

Staff working in intensive therapy units (ITUs) have known about the 'ITU syndrome' for many years. In spite of this the syndrome continues to occur. It is suggested that one of the reasons for this continued occurrence is that ITU staff place a lower priority on psychological care than they do on physical care. In this paper the potential seriousness of the ITU syndrome is emphasised by describing it as a form of torture. Publications from Amnesty International which describe methods of psychological torture are provided to support this suggestion. The analogies between psychological torture and ITU care are explored, and this is followed by consideration of ways of reducing the incidence of the syndrome and a suggested method of auditing an ITU in order to identify potential problem areas.

Critical Care↗
PubMed2000

Colinearity and gene density in grass genomes.

Grasses are the single most important plant family in agriculture. In the past years, comparative genetic mapping has revealed conserved gene order (colinearity) among many grass species. Recently, the first studies at gene level have demonstrated that microcolinearity of genes is less conserved: small scale rearrangements and deletions complicate the microcolinearity between closely related species, such as sorghum and maize, but also between rice and other crop plants. In spite of these problems, rice remains the model plant for grasses as there is limited useful colinearity between Arabidopsis and grasses. However, studies in rice have to be complemented by more intensive genetic work on grass species with large genomes (maize, Triticeae). Gene-rich chromosomal regions in species with large genomes, such as wheat, have a high gene density and are ideal targets for partial genome sequencing.

Arabidopsis↗
PubMed2005

Interpretation and implementation of oxygen uptake kinetics studies in children with spastic cerebral palsy.

From the scant data available, it seems that children with CP have a low maximum Vo2, a high O2 cost of submaximal exercise, and inefficient gait mechanics characterized by high levels of co-contraction. Despite the non-steady-state nature of habitual activity, there seem to be no published data focusing on Vo2 kinetics in children with CP Before measuring Vo2 kinetics, the noise content of the data needs to be examined because this has important implications for estimating tau Vo2 values. On the basis of the preliminary findings presented here, the breath-by-breath Vo2 responses of children with CP seem to have a similar noise magnitude to those of typically developing children; however, because they have smaller response amplitudes, the averaging of several repeated trials will be even more important than in typically developing children. Thorough habituation will be required to enable participants to complete the simulated step change exercise protocols that will enable Vo2 kinetics to be quantified. To facilitate appropriate comparisons with control groups on the basis of relative exercise intensities, further work is needed to establish the efficacy of estimating T(Lac) from gas exchange data in children with CP. By measuring Vo2, kinetics in children with CP, it is hoped that we will not only gain valuable insights into their exercise intolerance, but we will also have an important tool for assessing the effects of interventions using submaximal, and therefore less strenuous, exercise.

Adult↗
PubMed1991

Psychosocial family intervention in schizophrenia: a review of empirical studies.

This paper reviews the recent empirical studies on psychosocial family intervention in schizophrenia. Six family educational intervention studies and five more intensive family work studies with 2-year follow-up have been included. A series of questions is asked relating to the effects of such interventions, the efficacy of the different educational models, the active ingredients of these multi-component treatment packages, and the contribution of this new generation of studies to our understanding of the mechanisms through which these interventions work. Suggestions for further research are made. Finally, from the published manuals, the common components of these diverse, multi-component treatment packages of different family-intervention studies are identified.

Combined Modality Therapy↗