SEARCH · PubMed Health

Results for “modularity”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 37 records · Page 2Linked to original sources

PubMed1990

An extendable modular endoprosthetic system for bone tumour management in the leg.

A modular endoprosthetic system has been developed at the Groningen University Hospital and the University of Twente. The system can bridge a defect resulting from the resection of a malignant bone tumour which has developed around the knee joint of a child. Since the other healthy leg continues to grow, the system includes an element whose length can be adjusted non-invasively by using an external magnetic field. In addition to this lengthening element, there are one hip and two knee components, connectors of various lengths, and fixation elements. The paper describes the elements of the modular endoprosthetic system. Tables are created by means of which the elemental composition of such an endoprosthesis can be determined for each individual patient.

Adolescent↗

PubMed1976

Modular Formula: an approach to management of infants with specific or complex food intolerances.

Modular Formula is a dietary preparation for use in treating infants with complex malabsorptive disorders and for weaning infants from total parenteral nutrition. With this formula the physician can alter the quality of the various nutrients normally fed to infants as well as concentrations of those nutrients. Infants who cannot tolerate existing proprietary formulas will often thrive with the judicious use of this flexible formula. Modular Formula provides the clinician with a useful aid in the diagnosis and treatment of chronic diarrhea of infancy.

Diarrhea, Infantile↗

PubMed1989

In defense of a modular architecture for the number-processing system: reply to Campbell and Clark.

In several recent articles we have developed a model of the cognitive number-processing and calculation systems. Campbell and Clark (1988), commenting on one of these articles (McCloskey, Sokol, & Goodman, 1986), called into question our model's assumption of a modular functional architecture and a single form of internal numerical representation. Campbell and Clark proposed as an alternative a nonmodular encoding-complex view. In this reply we discuss the results offered by Campbell and Clark as evidence against our model, arguing that several of these results are in fact consistent with the model and that the remaining results, while raising significant issues, by no means justify abandonment of the modular framework and the constraints it imposes. We also point out that whereas our model provides specific, well-motivated interpretations for a substantial body of empirical findings, the encoding-complex view is so underspecified and unconstrained as to be vacuous.

Brain Damage, Chronic↗

PubMed1991

Modular integrated fluidized bed bioreactor technology.

We describe the design and demonstrate the application of a modular integrated fluidized bed bioreactor system. Basically the system is a reactor vessel equipped with an extending cylinder and a liquid distributor plate. Instead of an external recirculation loop, as used in existing fluidized bed systems, a low shear stress impeller is used as the recirculation pump. The system has several unique features, such as modular exchangeable elements, efficient oxygenation and the option of operating as a stirred tank-, a packed bed- or a fluidized bed reactor. An example of a fluidized bed run using CHO-K1 cells is shown. Under standard culture conditions a 100-fold increase in cell density (up to 1.2 x 10(8) cells/ml) was achieved.

Animals↗

PubMed1990

Modular mutagenesis of human placental ribonuclease inhibitor, a protein with leucine-rich repeats.

Human placental ribonuclease inhibitor (PRI) is a potent protein inhibitor of pancreatic ribonucleases and the homologous blood vessel-inducing protein angiogenin. Although inhibition by PRI occurs with a 1:1 stoichiometry, its primary structure is composed predominantly of seven internal leucine-rich repeats. These internal repeats were systematically deleted either singly or in combination by "modular" mutagenesis. Deletion of repeat units 3 plus 4 or repeat unit 6 results in mutants that both bind to and inhibit ribonuclease A. Therefore, the angiogenin/ribonuclease binding site in PRI must reside primarily or entirely in repeats 1, 2, 5, or 7, the short N- or C-terminal segments, or a combination of these. Deletion of repeat units 3-5, 5-6, or 5 alone results in mutants that exhibit only binding activity. Hence, the binding site cannot reside exclusively in repeat 5. Other internal deletions or N- or C-terminal deletions of 6-86% of the protein all abolish activity. These results suggest that PRI has a modular structure, with one primary structural repeat constituting one module. The approach taken may be applicable to other proteins with repeat structures.

Amino Acid Sequence↗

PubMed1991

Neuroscience, modularity and personality theory: conceptual foundations of a model of complex human functioning.

The purpose of this paper is to lay the groundwork for the development of a scientific theory of complex human functioning. We first discuss the assumptions on which our thinking is based, then advance the argument that behavior, and human activity in general, may be more fully understood in light of current data on the structural organization of the central nervous system. The brain is organized as a modular, distributed, self-organizing system, which is in constant transaction with the environment. Because of its plasticity, structural and functional change occurs in the brain as a result of experience throughout life. It is our thesis that complex human behavior is organized in a similar manner - that is, human personality and behavior manifest themselves as modular systems. The insights provided by an understanding of the relationship of brain and behavior may enhance the capacity to explain both normal and pathological personality functioning.

Adaptation, Psychological↗

PubMed1991

Modular indirect calorimeter suitable for long-term measurements in multipatient intensive care units.

OBJECTIVE: The construction of an indirect calorimeter capable of long-term automated sequential monitoring of multiple patients in adult and pediatric ICUs. DESIGN: A prototype system utilizing modular engineering principles, including central respiratory mass spectrometer; validation by organic solvent combustion and nitrogen dilution methods, and Tissot spirometer. SETTING: Surgical and pediatric ICUs in a tertiary care university hospital. RESULTS: When expired minute volume was measured over a range of 4 to 28 L in six intubated patients, expired minute volume measured by the prototype system demonstrated a correlation coefficient of .998 compared with simultaneous expired minute volume measured by a Tissot spirometer. Organic solvent combustion demonstrated a maximum error of 3.8% for oxygen consumption (VO2) and an average error of 1.73 +/- 1.25% (SEM). The maximum error for the respiratory quotient was 3.0%, with an average error of 1.75 +/- 1.07%. VO2 (predicted) vs. VO2 (measured) demonstrated a correlation coefficient of .997. Validation with the nitrogen dilution method over a range of FIO2 from 0.21 to 0.60 demonstrated a maximum error of 7.9%, with an average error of -1.72 +/- 1.1% (n = 51). CONCLUSIONS: Indirect calorimetry by means of a shared system for measurements in multiple patients in ICUs is feasible and cost effective utilizing modular principles and a centralized respiratory gas analyzer.

Adult↗

PubMed1990

Construction of modular circuits in the mammalian brain.

Comparison of seemingly different modular units in the mammalian brain raises the possibility of a common mechanism for their formation: the growth of neuropil mediated by trophic interactions. The ongoing postnatal construction of modular circuits according to trophic interplay may in turn account for the remarkable plasticity of the juvenile brain. By the same token, the normal waning of circuit construction during postnatal development may explain the end of critical periods, the diminished ability to recover from injury in older animals, and the decline with increasing age in the ability of mammals to learn complex skills.

Animals↗

PubMed1975

The Denver universal microspectroradiometer (DUM). II. Computer configuration and modular programming for radiometry.

This paper describes and discusses for microscopists and spectroscopists the choice of computer equipment and the design of programs used in the Denver Universal Microspectroradiometer (DUM). This instrument is an accurate computerized photon-counting microspectrophotometer, microspectrofluorimeter and microrefractometer. The computer is used to control the operation of the system, to acquire radiometric data of various kinds, and to reduce, analyse and output the data in a readily usable form. Since the radiometer was designed to carry out many kinds of measurements in a variety of micro- and macroscopic specimens, and since different methods of microscopy or spectroscopy have to be combined in various ways fro the study of any one specimen, no single master-program could fulfill efficiently all foreseeable requirements. Therefore, the programming developed is interactive, modular, hierarchical and hybrid. Modular interactive programming makes it possible for almost any kind of main program, applicable to almost any kind of measurement, to be assembled quickly from a collection of hierarchical subroutines. Main programs are short and composed mainly of Fortran statements calling subroutines; subroutines, in turn, automatically call other subroutines over many levels. The subroutines are independently written and optimized for maximum operational efficiency in the computer system used, or for maximum ease of transfer to other systems. This approach to programming enables someone unfamiliar with computer languages to operate the radiometric system from the console of the CRT terminal. The writing of new main programs, by linking groups of existing subroutines, requires only a minimum acquaintance with Fortran; only the writing and revision of subroutines requires programming experience. Differences and similarities in the method of computer operation between the present system and other computerized radiometers are briefly discussed.

Computers↗

PubMed1991

Corrosion of modular hip prostheses.

Nine uncemented hip prostheses of modular design were revised because of late infection (2 cases), femoral stem loosening or fracture (2), loosening of threaded cups (3) and protrusion of bipolar cups (2). At surgery we found tissue discoloration and macroscopic corrosion in four of the nine prostheses, located at the head-neck junction. Histological examination in most cases showed extensive necrosis associated with metal particles, indicating metal toxicity. Metallographic examination of the prosthetic heads revealed structural imperfections and inhomogeneity of the metal. We suggest that the crevice between the head and neck is a potential site of corrosion in modular designs.

Adolescent↗

PubMed2025

Modularization of the type II secretion gene cluster from Xanthomonas euvesicatoria facilitates the identification of a structurally conserved XpsCLM assembly platform complex.

Many bacterial pathogens depend on a type II secretion (T2S) system to secrete virulence factors from the periplasm into the extracellular milieu. T2S systems consist of an outer membrane secretin channel, a periplasmic pseudopilus and an inner membrane-associated assembly platform including a cytoplasmic ATPase. The components of T2S systems are often conserved in different bacterial species, however, the architecture of the assembly platform is largely unknown. Here, we analysed predicted assembly platform components of the Xps-T2S system from the plant-pathogenic bacterium Xanthomonas euvesicatoria. To facilitate these studies, we generated a modular xps-T2S gene cluster by Golden Gate assembly of single promoter and gene fragments. The modular design allowed the efficient deletion and replacement of T2S genes and the insertion of reporter fusions. Mutant approaches as well as interaction and crosslinking studies showed that the predicted assembly platform components XpsC, XpsL and XpsM form a trimeric complex which is essential for T2S and associates with the cytoplasmic ATPase XpsE and the secretin XpsD. Structural modeling revealed a similar trimeric architecture of XpsCLM homologs from Pseudomonas, Vibrio and Klebsiella species, despite overall low amino acid sequence similarities. In X. euvesicatoria, crosslinking and fluorescence microscopy studies showed that the formation of the XpsCLM complex is independent of the secretin and vice versa, suggesting that the assembly of the T2S system is a dynamic process which involves the association of preformed subcomplexes.

Xanthomonas↗

PubMed1992

Modular hemiarthroplasty for fractures of the proximal part of the humerus.

A new biomodular prosthesis was used for the treatment of a displaced fracture of the proximal part of the humerus in twenty-two shoulders in twenty-two patients. The fractures were classified according to the Neer system; there were thirteen four-part, five three-part, and four head-splitting fractures. There were fifteen women and seven men, and the mean age was seventy years (range, forty-nine to eighty-seven years). The hemiarthroplasty was performed an average of eleven days (range, one to forty-five days) after the injury. The deltopectoral interval was used in all patients, and the prosthesis was implanted with cement in twenty of the shoulders. All of the patients participated in a supervised program of rehabilitation. The patients were followed for an average of thirty-six months (range, twenty-six to forty-nine months). Twenty of the twenty-two patients had a good or excellent result. The active forward elevation averaged 119 degrees; external rotation, 40 degrees; and internal rotation, to the twelfth thoracic vertebra. All of the patients except for the two who had a poor result had satisfactory relief of pain. The two patients who had a poor result had a successful revision with a modular prosthesis of the same design. The modular head could be removed, enabling the surgeon to gain access to the glenoid and to adjust the soft tissues. The over-all scores correlated inversely with the age of the patients and the interval from the injury to the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1991

Resection of malignant bone tumors about the shoulder. A preliminary report of reconstruction with a new modular spacer.

Reconstruction after resection of malignant bone tumors about the shoulder is difficult. Twelve patients had reconstruction using a new titanium modular spacer. This modular system allows the surgeon to reconstruct variable lengths of the proximal humerus. Although the patient has no active shoulder motion, excellent hand and elbow function is preserved. The spacer serves as a temporary device in the young active patient. A more definitive reconstructive procedure can be performed after the completion of chemotherapy and a sufficient disease-free interval.

Adolescent↗

PubMedDate not supplied

[Preparation of and stability studies on enteral modular diets at the Pharmacy Service].

It is generally admitted fact in daily medical practice in some patients who require to be fed artificially, the treatment must always be directed, whenever possible, through "enteral route". There are patients whose nutritional needs cannot adapt to the standardized diets available in the market. In these cases it is necessary to draw up individualized diets for them, planned derived from the modules. It is equally known that there is always a problem to obtain, at the available means in the pharmaceutical services, established modular diets. It is described in this report a method of planning a modular enteral diets, physic-chemically stable and contaminating bacteria free. It is also detailed the election of adequate emulsion and stabilizer and the final concentration of each of these in the diets of different composition quali and quantitatively.

Enteral Nutrition↗

PubMed1989

Intrastriatal grafts derived from fetal striatal primordia. I. Phenotypy and modular organization.

Fetal striatal grafts display a striking modularity of composition. With acetylcholinesterase (AChE) histochemistry, the tissue of such grafts can be divided into regions with strong AChE staining of the neuropil and regions in which AChE staining of the neuropil is weak. In the experiments reported here, we reexamined the nature of this modularity. Striatal grafts were made by injecting dissociated cells of E15 ganglionic eminence into the striatum of adult rats, which 7 days before had recived intrastriatal deposits of ibotenic acid. Some donors had been exposed to 3H-thymidine at E11-E15. After 9-17 month survivals, the anatomical organization of the grafts was studied by histochemistry, immunohistochemistry, and autoradiography. In every graft, the AChE-rich regions formed patches (P regions) in a larger AChE-poor surround (NP regions). Neurons labeled with 3H-thymidine appeared in both P and NP regions, suggesting that donor cells were distributed in each type of region and that neither type of tissue, P or NP, was composed exclusively of host tissue. In the AChE-rich P regions, markers characteristic of normal perinatal and mature rat striatum were expressed by medium-sized cells: calcium-binding protein (calbindin D28k) immunostaining, metenkephalin (mENK) immunostaining, and, more rarely, somatostatin (SOM) immunostaining. In the NP regions, however, medium-sized cells expressing calbindin and mENK immunostaining were very rare, and there was an abundance of neuronal types not found in normal mature striatal tissue. These included (1) large, multipolar, calbindin-positive neurons with well-ramified, densely stained dendrites, (2) large, SOM-positive neurons with prominent dendritic trees, and (3) mENK-positive cells smaller than typical striatal, medium-sized, mENK-immunoreactive neurons. In Nissl stains, the AChE-rich P regions resembled the normal striatum of mature animals, whereas the AChE-poor NP regions did not. These findings suggest that the P regions of fetal striatal grafts achieve a phenotypy similar to that of normal striatum at maturity and during much of postnatal development. The dominant expression of perikaryal calbindin-like immunoreactivity in the P regions further suggests that these zones have a high proportion of tissue resembling striatal matrix. By contrast, expression of marker antigens in the NP zones of the grafts suggests that these zones are predominantly composed of nonstriatal tissue or that they have the phenotypy of immature striatum intermixed with some nonstriatal cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗

PubMedDate not supplied

[Modular diet and parenteral support in persistent diarrhea].

Eleven infants with protracted diarrhea were treated with modular diet and short-term parenteral nutrition. Mean age at admission was 3.7 months with males predominating. Enteropathogenic E. coli, classic serotypes, were isolated from 7 patients and rotavirus from one. A child with combined, severe immunodeficiency died. Milk protein intolerance was diagnosed in another patient. Balance studies and peroral biopsies were performed. Malnutrition was more frequent and hospital stay was longer in those infants who developed nosocomial infections. Even though this treatment shortened the duration of the hospitalization, the negative nutritional impact persisted: Weight/Age (NCHS) decreased from 84% to 61%, with rapid recovery after discharge. Fecal lactic acid excretion was increased on admission to 1,296 mg x day and disaccharidase activity was decreased. The modular diet decreased both fecal volume and lactic acid excretion.

Diarrhea, Infantile↗

PubMed1979

[Modular way of sampling for determination of the degree of occupational exposure at industrial plants with periodically changing dust concentration].

A work station with dustiness changing periodically during a workshift is one of the most common types of work stations, as regards exposure dynamics. Cyclic significant concentrations of dust occurring from time to time result from a specific technological treatment used. The measuring module will be the time of measurement, starting with the beginning of the cycle of working out a given detail or--the technological process through the whole treating and technological process as well as breaks--due to various reasons--until starting another, analogous operation. What was found is that average dust concentrations obtained from modular measurements correspond to average concentration to which an employee is exposed during the whole workshift. Modular measurements allow to reconstruct work conditions inducing silicosis, and may be helpful in settling the maximum allowable concentration.

Air Pollutants↗

PubMed2026

Systematic modular engineering of genome-integrated Escherichia coli MG1655 for high-level 2'-fucosyllactose production.

2'-Fucosyllactose (2'-FL), the most abundant human milk oligosaccharide (HMO), has attracted considerable interest for its prebiotic and immunomodulatory functions, with broad applications in infant nutrition. In this study, we report the development of a high-yield, genome-integrated 2'-FL-producing strain based on Escherichia coli MG1655 through systematic modular optimization. Starting from a single-copy BKHT strain (MGC06), we first optimized the copy number of the α-1,2-fucosyltransferase (α-1,2-FT) gene BKHT. Subsequently, the GDP-L-fucose supply was enhanced through coordinated genomic integration of the gene clusters cpsG-cpsB and gmd-fcl, while the multidrug efflux transporter gene mdfA was integrated to improve product export and strain robustness. BKHT copy number was then re-evaluated in the optimized background, with four copies yielding the highest production. The final engineered strain, harboring all genetic modifications stably integrated into the chromosome, produced 17.18 g/L 2'-FL in shake-flask culture. In fed-batch fermentation using a 5-L bioreactor, this strain achieved a titer of 154.12 g/L after 60 h, with a productivity of 2.57 g/L/h. Notably, throughout the entire fermentation process, no antibiotics or inducers were supplemented, underscoring the genetic stability and regulatory compliance of this plasmid-free system. To our knowledge, this represents the highest 2'-FL titer reported to date, positioning our engineered strain as a promising candidate for commercial 2'-FL production.

Escherichia coli↗