Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Problem Formulation”

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 1,693 records · Page 94Linked to original sources
PubMedDate not supplied

[Diet therapy of severe obesity].

In the last decades there has been a dramatic increase of obese subjects in many countries with the subsequent increase of health related problems, such as diabetes, hypertension, cardiovascular diseases. Even though several differential approaches, as media communication, guidelines formulation, have been performed in many different countries to solve this burden global health problem, no satisfactory results have been obtained. Personalized nutritional programs have been selected by obese subjects. Thus the correct approach would be to prescribe a caloric restricted diet in order to achieve long term weight loss in overweight or obese people. The aim in planning weight-reduction diets is that total food intake should meet recommended dietary allowance/adequate intake levels with the maintenance of the equilibrium among nutrients. If the nutritional approach fails or it is not sufficient to obtain significant weight loss, bariatric surgical intervention has been developed for the treatment of morbid-obese patients or severe obese patients with comorbidities as recommended by the American Society for Bariatric Surgery (A.S.B.S.) guidelines.

Bariatric Surgery↗
PubMed1998

Improving protein therapeutics with sustained-release formulations.

Although numerous protein therapeutics have been approved or are in advanced clinical testing, the development of more sophisticated delivery systems for this rapidly expanding class of therapeutic agents has not kept pace. The short in vivo half-lives, the physical and chemical instability, and the low oral bioavailability of proteins currently necessitate their administration by frequent injections of protein solutions. This problem can be overcome by use of injectable depot formulations in which the protein is encapsulated in, and released slowly from, microspheres made of biodegradable polymers. Although the first report of sustained release of a microencapsulated protein was more than 20 years ago, the instability of proteins in these dosage forms has prevented their clinical use. Advances in protein stabilization, however, have allowed development of sustained-release forms of several therapeutic proteins, and clinical testing of a monthly formulation human growth hormone is currently in progress. The obvious advantage of this method of delivery is that the protein is administered less frequently, sometimes at lower overall doses, than when formulated as a solution. More importantly, it can justify commercial development of proteins that, for a variety of reasons, could not be marketed as solution formulations.

Animals↗
PubMed2000

Lipids, lipophilic drugs, and oral drug delivery-some emerging concepts.

Lipid-based dose forms, which encompass a wide variety of compositional and functional characteristics, can be advantageously utilized for the formulation of lipophilic drugs. There has been a traditional reluctance to develop lipid-based dose forms due to potential problems of chemical and physical instability, and a paucity of knowledge regarding formulation design algorithms and technology transfer issues. However, there is a current resurgence of interest in lipid-based dose forms due to potential commercial and pharmaceutical benefits, and the industry trend towards the discovery/development of increasingly hydrophobic (and potent) new chemical entities. This mini-review describes some emerging formulation and biopharmaceutic strategies that hold promise for better understanding how to design and evaluate lipid-based dose forms.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2003

Three-dimensional morphometry of the femoral condyles.

OBJECTIVE: The present study describes the geometry of the three-dimensional articular surfaces of the human femoral condyles based on measurements of surface coordinates. DESIGN: The purpose was not to obtain a complex representation of one single condyle, but to describe the femoral condyles using simple geometric parameters based on measurements using a number of specimens. BACKGROUND: In joint modeling, a representative knee joint geometry is often desired which requires an approximation of the irregular joint geometry while taking into account interspecimen variations. METHODS: An optical device was used to measure the condylar articular surfaces of 12 human femurs in the femorotibial contact region. The sagittal profiles were reconstructed by means of two circular arcs and the radial profiles by means of one circular arc. RESULTS: The results provide the geometric parameters necessary for the three-dimensional reconstruction of the articular surfaces of the femoral condyles. The results indicate that the medial and lateral condyles of the distal femur are significantly asymmetric in a number of morphological features. CONCLUSION: The primary application of the results is expected to be in the formulation of finite element models of the knee joint for static contact problems. RELEVANCE: Numerical models of the knee joint are being widely used to study the mechanics of the joint. However, formulation of such models demands a prior knowledge of the complex three-dimensional geometry of the articular surfaces of the natural joint to establish the input parameters of the model.

Adult↗
PubMed1990

[Priority trends in scientific research on the problem of ischemic disorders of cerebrovascular circulation].

The authors characterize the current stage of studies into the problem of focal cerebral ischemia under experimental and clinical conditions, formulate research priorities in the prevention, pathogenesis, diagnosis and treatment of ischemic disturbances of cerebral circulation, demonstrate the significance of new approaches to and methods of solving disputable and unsolved problems of preventive and urgent angioneurology. Based on an analysis of the latest information, the authors distinguish the most important research data on the problem of ischemic disturbances of cerebral circulation and outline prospective ways of further scientific research endeavours.

Brain Ischemia↗
PubMed1993

The psychotherapy of core borderline psychopathology.

A psychodynamic formulation of borderline psychopathology includes the understanding of the borderline patient's aloneness problems, need-fear dilemma issues, and difficulties with primitive guilt. The aloneness problems are at the core of the disorder, and involve an inability to maintain an evocative memory, and holding and soothing introjects of significant people when under stress of separation. The possible childhood origins of these difficulties are explored and related to the ways these issues emerge in psychotherapy. The psychodynamic formulation is crucial in the psychotherapeutic approach to the aloneness problems. It helps the therapist work with the aloneness difficulties and understand the options as the therapy continues. Since rapid therapeutic decisions are often necessary with borderline patients, the formulation provides the necessary framework, and helps the therapist process and utilize countertransference feelings. Projective identification is an important concept that helps explain the complex transference/countertransference experiences, and is used in defining the resolution of the aloneness problems of borderline patients. Finally, limit-setting and the use of transitional objects are explored, utilizing the psychodynamic framework that has been defined.

Adult↗
PubMed1975

A survey of rural community mental health needs and resources.

The authors conducted a survey of 215 rural community mental health centers across the country to determine their unique problems, needs, and resources. From the 92 responses they received, they formulated a composite description of the rural mental health scene. Their description focuses on services offered, skills required to operate effective rural programs, and problems in the delivery of care and of evaluation. From the responses they also analyzed the extent of inservice training available to rural practitioners, the support systems needed, and the functions a proposed national task force on rural mental health could perform.

Community Mental Health Services↗
PubMed2003

Tunneling as a stochastic process: a path-integral model for microwave experiments.

Delay time results obtained in microwave experiments at frequencies above and below the cutoff frequency of different waveguide sections are interpreted on the basis of wave propagation in the presence of dissipative effects. Kac's original suggestion was the starting point for the formulation of a stochastic model, which has now been substantially improved, also in relation to the transition-elements theory of Feynman-Hibbs. In this way, an approach to the problem is provided, which is completely distinct from the ones formulated elsewhere.

Journal Article↗
PubMed1983

Thinking disorder in depression.

This experiment demonstrated abstract reasoning deficits in depressed patients and detailed some of the components of cognition that may determine such deficits. Subjects were given a discrimination learning problem in which possible solutions had to be formulated and tested against new information. Depressed subjects performed more poorly on the task than controls. Two types of errors--inability to narrow down the set of possible solutions (poor "focusing") and perseveration on disconfirmed hypotheses--hampered the performance of depressed but not control subjects. While logic, memory, and attention were intact at an elementary level, the inability to coordinate these functions in a complex task appeared to be an important feature of the depressive impairment.

Adult↗
PubMedDate not supplied

Chymodiactin postmarketing surveillance. Demographic and adverse experience data in 29,075 patients.

Postmarketing surveillance data on 29,075 patients who received Chymodiactin (Smith Laboratories' formulation of chymopapain) intradiscal injections for a herniated lumbar intervertebral disc are summarized and tabulated. The serious adverse reactions reported include death, anaphylaxis, paraplegia, and discitis. Similar problems also have been reported for Discase (Baxter-Travenol's formulation of chymopapain). Of 11 deaths reported following Chymodiactin administration, only 3 appear to be related to the drug or procedure. Two of these three were due to anaphylaxis and the third to bacterial discitis with resultant meningitis. Paraplegia appeared to be primarily due to needle trauma or injection of contrast agent and enzyme into the subarachnoid space. Careful patient selection and needle placement are essential for avoiding serious problems.

Adolescent↗
PubMedDate not supplied

Brimonidine formulation in polyacrylic acid nanoparticles for ophthalmic delivery.

In ocular drug delivery, a major problem is providing an adequate concentration of a therapeutic agent in the precorneal area. Mucoadhesive carriers such as polyacrylic acid in sub-colloidal, nanoparticulate form, have a strong potential for ophthalmic drug delivery. A formulation of brimonidine loaded in polyacrylic acid nanoparticles has been prepared for potential delivery in ophthalmic therapy. The particles were prepared by a reverse microemulsion polymerization technique and their sizes were in the range of 50 nm. In a preliminary biocompatibility test, Caco-2 cells (human primary colonic tumour adenocarcinoma) and human corneal epithelial cells incubated with polyacrylic acid nanoparticles were found to retain their viability over varying times. The loading efficiency of the drug brimonidine in the particles was shown to be between 80-85% and pH dependent. The bioadhesive polyacrylic hydrogel nanoparticles, used in the present study, exhibited superior loading properties for brimonidine, and the formulation was stable for more than 5 weeks. When the drug-loaded nanoparticles were dispersed in a phosphate buffer saline (pH = 7.4), the drug was slowly released over several hours. Two-photon laser scanning microscopic studies of dye-conjugated polyacrylic acid nanoparticles demonstrated the accumulation of the particles on the surface and intercellular spaces of Caco-2 cells.

Acrylic Resins↗
PubMed2006

The use of a Cissus quadrangularis formulation in the management of weight loss and metabolic syndrome.

AIM: Once considered a problem of developed countries, obesity and obesity-related complications (such as metabolic syndrome) are rapidly spreading around the globe. The purpose of the present study was to investigate the use of a Cissus quadrangularis formulation in the management of metabolic syndrome, particularly weight loss and central obesity. METHODS: The study was a randomized, double-blind, placebo-controlled design involving 123 overweight and obese persons (47.2% male; 52.8% female; ages 19-50). The 92 obese (BMI >30) participants were randomized into three groups; placebo, formulation/no diet, and formulation/diet (2100-2200 calories/day). The 31 overweight participants (BMI = 25-29) formed a fourth (no diet) treatment group. All participants received two daily doses of the formulation or placebo and remained on a normal or calorie-controlled diet for 8 weeks. RESULTS: At the end of the trial period, statistically significant net reductions in weight and central obesity, as well as in fasting blood glucose, total cholesterol, LDL-cholesterol, triglycerides, and C-reactive protein were observed in participants who received the formulation, regardless of diet. CONCLUSION: Cissus quadrangularis formulation appears to be useful in the management of weight loss and metabolic syndrome.

Adult↗
PubMed2004

Efficient formulation of the stochastic simulation algorithm for chemically reacting systems.

In this paper we examine the different formulations of Gillespie's stochastic simulation algorithm (SSA) [D. Gillespie, J. Phys. Chem. 81, 2340 (1977)] with respect to computational efficiency, and propose an optimization to improve the efficiency of the direct method. Based on careful timing studies and an analysis of the time-consuming operations, we conclude that for most practical problems the optimized direct method is the most efficient formulation of SSA. This is in contrast to the widely held belief that Gibson and Bruck's next reaction method [M. Gibson and J. Bruck, J. Phys. Chem. A 104, 1876 (2000)] is the best way to implement the SSA for large systems. Our analysis explains the source of the discrepancy.

Journal Article↗
PubMed2006

A study of the collisional fragmentation problem using the Gamma distribution approximation.

The nonlinear fragmentation population balance formulation has been elevated in recent years from a prototype for studying nonlinear integro-differential equations to a vehicle for analyzing and understanding several physicochemical processes of technological interest. The so-called pure collisional fragmentation, which is the particular mode of nonlinear fragmentation induced by collisions between particles, is studied here. It is shown that the corresponding population balance equation admits large time asymptotic (self-similarity) solutions for homogeneous fragmentation and collision functions (kernels). The self-similar solutions are given in closed form for some simple kernels. Based on the shape of the self-similar solutions the method of moments with Gamma distribution approximation is employed for transient solution (from initial state to establishment of the asymptotic shape) of the collisional fragmentation equation. These solutions are presented for several sets of parameters and their behavior is discussed rather extensively. The present study is similar to the one has already been performed for the case of the much simpler linear fragmentation equation [G. Madras, B.J. McCoy, AIChE J. 44 (1998) 647].

Chemical Phenomena↗
PubMed2006

The electronic ground-state energy problem: a new reduced density matrix approach.

We present here a formulation of the electronic ground-state energy in terms of the second order reduced density matrix, using a duality argument. It is shown that the computation of the ground-state energy reduces to the search of the projection of some two-electron reduced Hamiltonian on the dual cone of N-representability conditions. Some numerical results validate the approach, both for equilibrium geometries and for the dissociation curve of N(2).

Journal Article↗
PubMed2002

A dimensionless mobility formulation for evaluation of force and moment excitation of structures.

The problem addressed is the simultaneous excitation of a structure by a force and moment. These two forms of excitation are dimensionally incompatible, and so their relative importance is normally difficult to assess. Here, a dimensionless form of the mobility matrix is developed thereby allowing proper comparison. The off-diagonal elements of the matrix quantify the coupling between two excitations of whatever dimensions, in other words the extent to which an applied force or moment affects the power input by another force or moment. It is shown that off-diagonals of unit magnitude indicate the maximum possible extent of coupling between the corresponding excitations. A precise definition of weak and strong coupling is therefore possible. Illustrative examples of dimensionless mobilities for infinite, semi-infinite, and finite plates are given. It is also shown that the eigenvalues of the dimensionless mobility matrix relate the actual delivered power to the "point-by-point" power input. The results are shown to have wider relevance than originally intended; specifically, the dimensionless mobilities provide a measure of the suitability for active vibration control of different points on a structure, or mixed excitations.

Journal Article↗
PubMed2004

[EBM: otitis media in children: how to formulate a PICO question].

This series of articles begins with a problem frequently encountered in children: acute otitis media. Under the insistence of parents, antibiotics are frequently prescribed. The physician knows that the value of that therapy is debatable, but what for a child of 6 years of age? The physician whishes to compare his/her opinion with what is published in the litterature or available on the web. How to start his/her research? In this first article the physician will find out how to translate his/her practical question into a question which leads to a practical answer, and then to a PICO question. This will allow the physician to find sources of directly usable and relevant data which will offer a rational and wellfounded answer to his/her clinical question.

Child↗