Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “modularity”

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 451 records · Page 25Linked to original sources
PubMed2005

Function of the family-9 and family-22 carbohydrate-binding modules in a modular beta-1,3-1,4-glucanase/xylanase derived from Clostridium stercorarium Xyn10B.

Clostridium stercorarium Xyn10B having hydrolytic activities on xylan and beta-1,3-1,4-glucan is a modular enzyme composed of two family-22 carbohydrate-binding modules (CBMs), a family-10 catalytic module of the glycoside hydrolases, a family-9 CBM, and two S-layer homologous modules, consecutively from the N-terminus. We investigated the function of family-9 and family-22 CBMs in a modular enzyme by comparing the enzymatic properties of a truncated enzyme composed of two family-22 CBMs and the catalytic module (rCBM22-CM), an enzyme composed of the catalytic module and family-9 CBM (rCM-CBM9), an enzyme composed of two family-22 CBMs, the catalytic module, and family-9 CBM (rCBM22-CM-CBM9), and the catalytic module polypeptide (rCM). Although the addition of family-9 CBM to rCM and rCBM22-CM did not significantly change catalytic activity toward xylan and beta-1,3-1,4-glucan, the addition of family-22 CBM to rCM and rCM-CBM9 drastically enhanced catalytic activity toward xylan and especially beta-1,3-1,4-glucan. Furthermore, the addition of family-22 CBM to rCM and rCM-CBM9 shifted the optimum temperature from 65 degrees C to 75 degrees C, but that of family-9 CBM to rCM and rCBM22-CM did not affect the optimum temperature. These facts suggest that the enzyme properties of Xyn10B were mainly dependent on the presence of the family-22 CBMs but not family-9 CBM.

Base Sequence↗
PubMedDate not supplied

The Modular Propad and the Softform mattress.

Constant low-pressure supports such as soft mattresses can feel comfortable because they conform well to the shape of the body. When such mattresses are provided with a highly convoluted surface made up of contiguous foam pillars, their efficacy is improved. The Modular Propad is a highly convoluted, but shallow, foam mattress. It is used as an overlay for an ordinary mattress and seems to be superior to earlier forms of convoluted foam overlay. The Softform is a new mattress which has replaceable sections. The outermost sections of the Softform are convoluted foam sheets similar to the Modular Propad. This article discusses the advantages and disadvantages of these products and some potential problems with their covers. It also suggests that the use of a pressure sore risk assessment tool can facilitate the allocation of patients to these special supports.

Beds↗
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↗
PubMed1999

Nonunion of tibial stress fractures in patients with deformed arthritic knees. Treatment using modular total knee arthroplasty.

In two years we treated four women with ununited stress fractures of their proximal tibial diaphyses. They all had arthritis and valgus deformity. The stress fractures had been treated elsewhere by non-operative means in three patients and by open reduction and internal fixation in one, but had failed to unite. After treatment with a modular total knee prosthesis with a long tibial stem extension, all the fractures united. A modular total knee prosthesis is suitable for the rare and difficult problem of ununited tibial stress fractures in patients with deformed arthritic knees since it corrects the deformity and the adverse biomechanics at the fracture site, stabilises the fracture and treats the arthritis.

Aged↗
PubMed2005

Osteolysis in a surface-cemented, primary, modular Freeman-Samuelson total knee replacement.

We analysed at a mean follow-up of 7.25 years the clinical and radiological outcome of 117 patients (125 knees) who had undergone a primary, cemented, modular Freeman-Samuelson total knee replacement. While the tibial and femoral components were cemented, the patellar component was uncemented. A surface-cementing technique was used to secure the tibial components. A total of 82 knees was available for radiological assessment. Radiolucent lines were seen in 41 knees (50%) and osteolytic lesions were seen in 13 knees (16%). Asymptomatic, rotational loosening of the patellar implant was seen in four patients and osteolysis was more common in patients with a patellar resurfacing. Functional outcome scores were available for 41 patients (41 knees, 35%) and the mean Western Ontario McMasters Universities score was 77.5 (sd 19.5) and the cumulative survival was 93.4% at ten years with revision for aseptic loosening as an endpoint. Increased polyethylene wear from modular components, a rotationally-loose patella, and the surface-cementing technique may have contributed to the high rate of osteolysis seen in our study.

Aged↗
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↗
PubMed1997

Modular organization of Pax/homeodomain proteins in transcriptional regulation.

Specificity in transcriptional regulation lies in a large part in the specificity of DNA binding by transcription factors. One group of transcription factors which are of great interest for studying transcriptional specificity is the Pax/Homeodomain (Pax/HD) proteins which contain two conserved DNA binding domains, a paired domain (PD) and a Paired-class homeodomain (HD). The Pax/HD proteins can bind to at least three types of specific DNA sequences: the PD binding sites, the dimeric HD binding sites and a composite HD and PD binding site. We propose that Pax/HD proteins regulate different subsets of their target genes through modular binding to one of these three specific sequences. We show that, in a tissue culture system, a member of the Pax/HD family, Paired, is able to activate transcription after binding through either its PD or its HD. The transactivation mediated by one domain does not require DNA binding of the other domain. Furthermore, binding sites specific for the PD of Paired are sufficient to mediate embryonic expression of a reporter gene in a paired-like pattern. The expression of the reporter gene is dependent on wild type paired function and, in a prd mutant background, it can be rescued by an exogenous paired gene encoding a protein whose HD is not able to bind to DNA. Finally, we show that the Paired protein uses differently its C-terminal activation domain when transactivation is mediated through its PD or its HD. These results and recent evidence from other Pax/HD proteins strongly suggest that this class of proteins is able to achieve specific and modular transcriptional regulation through its multiple DNA binding domains.

Animals↗
PubMed1999

[Modular PC-based data acquisition and processing system for biological signals].

The data acquisition system described here is designed for biomedical research and permits the recording of up to eight biological signals simultaneously. A personal computer using the Windows 95 operating system is employed for data monitoring, data processing and analysis during experiments. The system has been designed for reliability, economy, flexibility and ease of handling, with the aim of achieving universal application. To avoid interface incompatibility, problems with transfer protocols and the data formats of commercially available products, analog signals are used for further processing. The individual input channels are electrically isolated from one another and the PC to avoid ground loops, and for reasons of safety. An isolated voltage supply is available for pre-amplifiers and bridges. A bandwidth of 0-5 kHz and the maximum sampling rate of 12.5 kHz suffice to pick up higher frequency signals such as EMG and ENG. The modular software and hardware concepts permit the use of almost any desktop or laptop PC as a central processing unit. The PC handless documentation, data acquisition, data analysis and the preparation of publications. If needed, further analytical functions can be added in modular form. Finally, the option of saving data in the ASCII format permits processing of results with such standard software packages as Excel, Access, Matlab and Origin.

Signal Processing, Computer-Assisted↗
PubMed2002

[A modular method for automated evaluation of gait analysis data].

A modular methodology for automated gait data evaluation: The aim of Instrumented Gait Analysis is to measure data such as joint kinematics or kinetics during gait in a quantitative way. The data evaluation for clinical purposes is often performed by experienced physicians (diagnosis of specific motion dysfunction, planning and validation of therapy). Due to subjective evaluation and complexity of the pathologies, there exists no objective, standardized data analysis method for these tasks. This article covers the development of a modular, computer-based methodology to quantify the degree of pathological gait in comparison to normal behavior, as well as to automatically search for interpretable gait abnormalities and to visualize the results. The outcomes are demonstrated with two different patient groups.

Biomechanical Phenomena↗
PubMed2005

Quantitative automated human chorionic gonadotropin measurement in urine using the Modular Analytics E170 module (Roche).

Ongoing demands on laboratory performance require optimization of processes. An obvious way to achieve this is to reduce manual labor in favor of automated methods. We describe the validation of an automated quantitative urine human chorionic gonadotropin (hCG) analysis on the Roche Modular E170 analyzer to replace the manual qualitative pregnancy test in urine. At urine hCG concentrations of 476, 45 and 11 U/L, we found inter-assay variation of 4.3%, 4.3% and 6.8% and average intra-assay variation of 3.0%, 2.6% and 3.0%, respectively. The analytical detection limit was 0.7 U/L. We did not detect any loss (due to degradation or adsorption) during a storage period of 5 days at 4 degrees C or at -20 degrees C. Recoveries of hCG in urine of a pregnant woman diluted with urine of a pre-menopausal non-pregnant woman (concentration range between 6 and 800 mU/L) were between 93% and 112% (y=0.997x-3.843, r 2 =0.999). Diluting a serum sample (hCG 42,000 U/L) with urine (negative for hCG) up to 8000-fold yielded a completely linear hCG response, indicating that the assay was not affected by the urine matrix. In a correlation study with 60 urine samples (of which 10 were of male origin), we did not find any discrepancies between results for the manual pregnancy test and the hCG test on the Roche Modular E170 (using a cutoff value of 50 U/L).

Analysis of Variance↗
PubMed2005

Single adhesive nanofibers from a live diatom have the signature fingerprint of modular proteins.

The adhesive and mechanical properties of a cell-substratum adhesive secreted by live diatom cells were examined in situ using atomic force microscopy. The resulting force curves have a regular saw-tooth pattern, the characteristic fingerprint of modular proteins, and when bridged between tip and surface can repeatedly be stretched and relaxed resulting in precisely overlaying saw-tooth curves (up to approximately 600 successive cycles). The average rupture force of the peaks is 0.794 +/- 0.007 (mean +/- SE) nN at a loading rate of 0.8 microm/s and the average persistence length is 0.026 +/- <0.001 (mean +/- SE) nm (fit using the worm-like chain model). We propose that we are pulling on single adhesive nanofibers, each a cohesive unit composed of a set number of modular proteins aligned in register. Furthermore, we can observe and differentiate when up to three adhesive nanofibers are pulled based upon multimodal distributions of force and persistence length. The high force required for bond rupture, high extensibility (approximately 1.2 microm), and the accurate and rapid refolding upon relaxation, together provide strong and flexible properties ideally suited for the cell-substratum adhesion of this fouling diatom and allow us to understand the mechanism responsible for the strength of adhesion.

Adhesiveness↗
PubMed1997

Horizontal projections of area 17 in Cebus monkeys: metric features, and modular and laminar distribution.

Metric features and modular and laminar distributions of intrinsic projections of area 17 were studied in Cebus apella. Anterogradely and retrogradely labeled cell appendages were obtained using both saturated pellets and iontophoretic injections of biocytin into the operculum. Laminar and modular distributions of the labeled processes were analyzed using Nissl counterstaining, and/or cytochrome oxidase and/or NADPH-diaphorase histochemistry. We distinguished three labeled cell types: pyramidal, star pyramidal and stellate cells located in supragranular cortical layers (principally in layers IIIa, IIIb alpha, IIIb beta and IIIc). Three distinct axon terminal morphologies were found, i.e., Ia, Ib and II located in granular and supragranular layers. Both complete and partial segregation of group I axon terminals relative to the limits of the blobs of V1 were found. The results are compatible with recent evidence of incomplete segregation of visual information flow in V1 of Old and New World primates.

Animals↗
PubMed1994

Migration of corrosion products from modular hip prostheses. Particle microanalysis and histopathological findings.

Migration of solid corrosion products from the modular head-neck junction of fifteen total hip replacements to the periprosthetic tissues was studied. The devices and tissues were recovered at the time of a revision procedure or at autopsy after a mean of sixty-four months (range, eight to ninety-seven months). The prostheses had a cobalt-chromium-alloy head coupled with a cobalt-chromium-alloy or a titanium-alloy stem. The solid corrosion product was identified by electron microprobe analysis and Fourier transform infrared microprobe spectroscopy as a chromium orthophosphate hydrate-rich material. The product was present at the junction of the modular head and neck and as particles within the periprosthetic tissues as early as eight months postoperatively. In several hips, it was also present on the polyethylene bearing surface. The particles in the tissues ranged in size from less than one to 500 micrometers. They were present within histiocytes or were surrounded by foreign-body giant cells in the pseudocapsule of the hip joint; in the membranes of the femoral bone-implant interface; and at sites of femoral endosteal erosions, with and without loosening of the femoral component.

Adult↗
PubMed1997

The press-fit condylar modular total knee system. Four-to-six-year results with a posterior-cruciate-substituting design.

One hundred and eighteen patients who had had 150 consecutive primary total knee replacements (sixteen bilateral procedures) between February 1988 and February 1990, with insertion of the press-fit condylar modular total knee system with cement, were enrolled in a prospective study. Ninety-six patients (125 knees) were followed for an adequate interval (mean, 4.8 years; range, 3.8 to 6.2 years). Thirteen patients (fifteen knees) died, and nine patients (ten knees) were lost to follow-up. The mean age of the patients at the time of the index arthroplasty was seventy years (range, twenty-nine to eighty-five years). The patients were evaluated clinically and radiographically, according to the scoring system of the Knee Society, and the results on a self-administered questionnaire were used to evaluate pain, function, satisfaction, and patellofemoral symptoms. A Kaplan-Meier survivorship analysis was performed with a revision operation as the end point. The mean functional and clinical scores, according to the system of the Knee Society, were 78 and 93 points, respectively, at the most recent follow-up examination. The result was excellent for 103 knees, good for thirteen, fair for three, and poor for six. Three revision operations were necessary: two because of infection and one because of instability. The over-all rate of patellofemoral symptoms was 8 per cent (ten knees). Three knees had tibiofemoral instability; subsequent modification of the design of the tibial cam decreased the prevalence of this problem. Non-progressive radiolucent lines were present at the cement-bone interface in 39 per cent (thirty-nine) of the ninety-nine knees that had complete radiographic follow-up. No prosthesis had loosened by the time of the most recent follow-up examination. The rate of survival of the implant was 97 per cent at six years, and the standard error of the mean was 1.6 per cent. In the present series, total knee arthroplasties with the press-fit condylar modular knee system resulted in excellent relief of pain, an excellent range of motion, and restoration of function. They were also associated with a low prevalence of patellofemoral problems.

Adult↗
PubMed2004

Clinical and radiographic results associated with a modern, cementless modular cup design in total hip arthroplasty.

BACKGROUND: First-generation cementless modular cups reproducibly achieved fixation to bone but were associated with unacceptable rates of pelvic osteolysis and mechanical failure. Consequently, second-generation cups were developed with shells that had a limited number of holes (or no holes) as well as improved locking mechanisms, a polished inner surface, and increased conformity with the liner. The purpose of the present study was to evaluate the clinical and radiographic results associated with the use of a second-generation acetabular component for primary total hip arthroplasty. METHODS: Two hundred and ninety-seven patients underwent 335 consecutive primary total hip arthroplasties that were performed by a single surgeon with a second-generation modular acetabular component. All cups were implanted with a press-fit technique. Ten patients were lost to follow-up, and sixteen died from unrelated causes. The remaining 271 patients (308 hips) were followed clinically (with the Hospital for Special Surgery hip-scoring system) and radiographically for four to seven years. RESULTS: One cup was revised because of aseptic loosening. There were seven additional revisions: five were performed because of aseptic loosening of the stem with a well-fixed cup, and two were performed because of deep infection. Among the 271 patients who were alive at the time of the last follow-up, 266 (98%) had retention of the cup and 264 (97%) had retention of both components with a good or excellent clinical result. In the group of 229 patients (262 hips) with complete radiographic follow-up, 259 cups were well fixed and the average wear rate (for the 246 hips for which this rate could be calculated) was 0.09 mm/yr. Osteolysis was detected in twelve hips (5%) and was associated with male gender (p = 0.001) and the annual wear rate (p = 0.004). The extent of calcar resorption was also associated with the annual wear rate (p < 0.001). CONCLUSIONS: This second-generation acetabular cup design predictably achieved bone fixation and was associated with low rates of revision for loosening and osteolysis after intermediate-term follow-up.

Adult↗
PubMed2004

Comparison of a hydroxyapatite-coated sleeve and a porous-coated sleeve with a modular revision hip stem. A prospective, randomized study.

BACKGROUND: Bone ingrowth into a cementless prosthesis can be achieved by both porous and hydroxyapatite coatings. The purpose of this study was to compare the performance of a hydroxyapatite-coated proximal sleeve and a porous bead-coated sleeve in patients managed with a modular revision hip system. METHODS: Between August 1992 and December 1996, fifty-three consecutive femoral revisions performed with an S-ROM stem in fifty-two patients were prospectively randomized at the time of surgery to either a hydroxyapatite-coated or a porous-coated sleeve. All patients were evaluated clinically and radiographically at three months, six months, and yearly for a minimum of two years (average, four years; range, two to 7.5 years). Femoral defects were classified according to the criteria of Paprosky et al. Six patients died and four patients were lost to follow-up, leaving forty-two patients (forty-three hips) as the final study group. RESULTS: For the entire group, two femoral stems, one of which had been implanted in a hip with a Paprosky type-II femoral defect and the other in a hip with a Paprosky type-IIIB femoral defect, required a repeat revision, one for pain and the other for aseptic loosening. Radiographic evidence of bone ingrowth was observed in 96% (twenty-six) of the twenty-seven femora with type-I or II defects and in 81% (thirteen) of the sixteen femora with type-III defects. Femoral component survival, with use of revision as the end point, was 95% at four years for the entire group. The Harris hip scores were not significantly different when stratified by implant type, but were significantly different when stratified by bone loss (p < 0.05). In the femora with type-I or II defects, no difference was detected between those treated with a hydroxyapatite-coated implant and those that received a porous-coated implant with respect to bone ingrowth. However, in femora with type-III defects, the likelihood of the development of bone ingrowth was 2.6 (95% confidence interval, 1.3 to 5.17) times greater in hips that received a hydroxyapatite-coated implant (all eight developed ingrowth) than in hips that had a porous-coated implant (five of eight developed ingrowth) (p = 0.05). CONCLUSIONS: Bone fixation was achieved more often with hydroxyapatite-coated sleeves in femora with Paprosky type-III defects, but no significant difference was noted in outcomes between the two implant types when used in bone with type-I or type-II femoral defects. Overall, the S-ROM modular hip stem performed better in femora with type-I or II bone defects than in femora with type-III defects. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See Instructions to Authors for a complete description of levels of evidence.

Adult↗
PubMed2005

Modular fixed-bearing total knee arthroplasty with retention of the posterior cruciate ligament. A study of patients followed for a minimum of fifteen years.

BACKGROUND: There have been a limited number of studies of total knee arthroplasties with durations of follow-up of fifteen years, but we are not aware of any involving modular fixed-bearing posterior cruciate-retaining prostheses. METHODS: A consecutive series of 139 total knee arthroplasties in 109 patients (average age, sixty-seven years), performed by one surgeon using a nonconforming posterior cruciate-retaining prosthesis, was followed for fifteen years or longer. Forty-five patients (fifty-nine knees) were examined at a minimum of fifteen years postoperatively, fifty-seven patients (seventy knees) had died, five patients (eight knees) were too ill to return for assessment, and two patients (two knees) were considered lost to follow-up. The patients were assessed clinically with use of the Knee Society clinical rating system, and the knees were assessed radiographically. Survivorship analysis was performed with use of worst-case-scenario analysis and with failure defined as a reoperation for any reason. RESULTS: There were five reoperations, four of which were performed because of wear of the polyethylene insert. In addition, one loose cemented femoral component was revised at fifteen years. The survival rate without revision or a need for any reoperation was 92.6% at fifteen years. The mean Knee Society score and functional score at fifteen years were 96 and 78 points, respectively. The prevalence of radiolucent lines was 13%, with 2% around the femur, 11% around the tibia, and none around the patella. None of these lines were clinically relevant. There was no evidence of progressive radiolucent lines, and there was one case of asymptomatic femoral osteolysis. CONCLUSIONS: In this single-surgeon series, modular fixed-bearing posterior cruciate-retaining total knee arthroplasties had good clinical and radiographic results with excellent survivorship for up to fifteen years. These results are comparable with those in long-term studies of posterior stabilized implants and of prostheses with mobile-bearing and nonmodular tibial inserts.

Adolescent↗
PubMed2004

Context-sensitive approach for interactive systems design: modular scenario-based methods for context representation.

As information technology becomes more ubiquitous in our work and daily life environments, understanding contexts of activities becomes critical to enhance a foundation for human-centered design practice. This research introduces a conceptual framework for defining, representing and incorporating contexts as core information for interactive systems design. Modular Scenario Composition Method was developed as a mechanism for linking descriptive field study information and analytical aspect models representing many viewpoints involved in the system development and use processes. Design Information Framework (DIF) previously developed by the author was used as a common information platform to bridge different information representation formats including scenarios and aspect models. By combining modular scenarios and aspect models representing contexts, chains of relations between contexts, their triggering factors, and their influences on user actions can explicitly be described.

Humans↗