1
|
Farooq MU, Anwar S, Kumar MS, AlFaify A, Ali MA, Kumar R, Haber R. A Novel Flushing Mechanism to Minimize Roughness and Dimensional Errors during Wire Electric Discharge Machining of Complex Profiles on Inconel 718. Materials (Basel) 2022; 15:7330. [PMID: 36295397 PMCID: PMC9607874 DOI: 10.3390/ma15207330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/12/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
One of the sustainability goals in the aeronautical industry includes developing cost-effective, high-performance engine components possessing complex curved geometries with excellent dimensional precision and surface quality. In this regard, several developments in wire electric discharge machining have been reported, but the influence of flushing attributes is not thoroughly investigated and is thus studied herein. The influence of four process variables, namely servo voltage, flushing pressure, nozzle diameter, and nozzle-workpiece distance, were analyzed on Inconel 718 in relation to geometrical errors (angular and radial deviations), spark gap formation, and arithmetic roughness. In this regard, thorough statistical and microscopical analyses are employed with mono- and multi-objective process optimization. The grey relational analysis affirms the reduction in the process's limitations, validated through confirmatory experimentation results as 0.109 mm spark gap, 0.956% angular deviation, 3.49% radial deviation, and 2.2 µm surface roughness. The novel flushing mechanism improved the spark gap by 1.92%, reducing angular and radial deviations by 8.24% and 29.11%, respectively.
Collapse
Affiliation(s)
| | - Saqib Anwar
- Industrial Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - M. Saravana Kumar
- Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 10608, Taiwan
| | - Abdullah AlFaify
- Industrial Engineering Department, College of Engineering, King Saud University, P.O. Box 800, Riyadh 11421, Saudi Arabia
| | - Muhammad Asad Ali
- Department of Industrial and Manufacturing Engineering, University of Engineering and Technology, Lahore 54890, Pakistan
| | - Raman Kumar
- Department of Mechanical and Production Engineering, Guru Nanak Dev Engineering College, Ludhiana 141006, India
| | - Rodolfo Haber
- Center for Automation and Robotics (CSIC-UPM), Spanish National Research Council-Technical University of Madrid, 28500 Madrid, Spain
| |
Collapse
|
2
|
Godoy J, Haber R, Muñoz JJ, Matía F, García Á. Smart Sensing of Pavement Temperature Based on Low-Cost Sensors and V2I Communications. Sensors (Basel) 2018; 18:s18072092. [PMID: 29966284 PMCID: PMC6068537 DOI: 10.3390/s18072092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 06/25/2018] [Accepted: 06/26/2018] [Indexed: 11/26/2022]
Abstract
Nowadays, the preservation, maintenance, rehabilitation, and improvement of road networks are key issues. Pavement condition is highly affected by environmental factors such as temperature and humidity, hence the importance of building databases enriched with real-time information from monitoring systems that enable the analysis and modeling of the road properties. Information and communication technologies, and specifically wireless sensor networks and computational intelligence methods, are enabling the design of new monitoring systems. The main goal of this work is the design of a pavement monitoring system for measuring temperature at internal layers. The proposed solution is based on low-cost and robust temperature sensors, vehicle-to-infrastructure communications, allowing one to transmit information directly from probes to a moving auscultation vehicle, and a neural network-based model for prediction pavement temperature. User requirements drive probes’ design to a modular device, with easy installation, low cost, and reduced energy consumption. Results of the test and validation experiments show both the benefits and viability of the proposed system, which reflect in an accuracy improvement and reduction in routine test duration. Finally, data collected over a year is applied to assess the performance of BELLS3 models and the suggested neural network for predicting pavement temperature. The dynamic behavior of the predicted temperature and the mean absolute error of the neural network-based model are better than the BELL3 model, demonstrating the suitability of the proposed pavement monitoring system.
Collapse
Affiliation(s)
- Jorge Godoy
- Centre for Automation and Robotics (UPM-CSIC), Universidad Politécnica de Madrid, Calle José Gutiérrez Abascal, 2, 28006 Madrid, Spain.
| | - Rodolfo Haber
- Centre for Automation and Robotics (UPM-CSIC), Consejo Superior de Investigaciones Científicas, Ctra. de Campo Real, km 0.200, Arganda del Rey, 28500 Madrid, Spain.
| | - Juan Jesús Muñoz
- GEOCISA Geotecnia y Cimientos S.A, Los Llanos de Jérez, 10-12, 28820 Coslada, Madrid, Spain.
| | - Fernando Matía
- Centre for Automation and Robotics (UPM-CSIC), Universidad Politécnica de Madrid, Calle José Gutiérrez Abascal, 2, 28006 Madrid, Spain.
| | - Álvaro García
- Centre for Automation and Robotics (UPM-CSIC), Consejo Superior de Investigaciones Científicas, Ctra. de Campo Real, km 0.200, Arganda del Rey, 28500 Madrid, Spain.
| |
Collapse
|
3
|
Zabet K, Rossiter JA, Haber R, Abdullah M. Pole-placement Predictive Functional Control for under-damped systems with real numbers algebra. ISA Trans 2017; 71:403-414. [PMID: 28867239 DOI: 10.1016/j.isatra.2017.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 05/31/2017] [Accepted: 08/02/2017] [Indexed: 06/07/2023]
Abstract
This paper presents the new algorithm of PP-PFC (Pole-placement Predictive Functional Control) for stable, linear under-damped higher-order processes. It is shown that while conventional PFC aims to get first-order exponential behavior, this is not always straightforward with significant under-damped modes and hence a pole-placement PFC algorithm is proposed which can be tuned more precisely to achieve the desired dynamics, but exploits complex number algebra and linear combinations in order to deliver guarantees of stability and performance. Nevertheless, practical implementation is easier by avoiding complex number algebra and hence a modified formulation of the PP-PFC algorithm is also presented which utilises just real numbers while retaining the key attributes of simple algebra, coding and tuning. The potential advantages are demonstrated with numerical examples and real-time control of a laboratory plant.
Collapse
Affiliation(s)
- K Zabet
- Cologne Univ. of Applied Sciences, Inst. of Plant and Process Engineering, Betzdorfer Str. 2, D-50679 Koeln, Germany
| | - J A Rossiter
- Dept. of Automatic Control and Systems Eng., University of Sheffield, S1 3JD, UK.
| | - R Haber
- Cologne Univ. of Applied Sciences, Inst. of Plant and Process Engineering, Betzdorfer Str. 2, D-50679 Koeln, Germany.
| | - M Abdullah
- Dept. of Automatic Control and Systems Eng., University of Sheffield, S1 3JD, UK
| |
Collapse
|
4
|
Haber R, Bourrat E, Derache AF, Rivet J, Bagot M, Dalle JH, Bouaziz JD. Image Gallery: Juvenile cutaneous chronic graft-versus-host disease presenting as bullous pemphigoid. Br J Dermatol 2017; 177:e69. [PMID: 28940263 DOI: 10.1111/bjd.15763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R Haber
- Service de Dermatologie, AP-HP, Université Paris VII Sorbonne Paris Cité, Hôpital Saint-Louis, Paris, France
| | - E Bourrat
- Service de Dermatologie, AP-HP, Université Paris VII Sorbonne Paris Cité, Hôpital Saint-Louis, Paris, France
| | - A-F Derache
- Service d'Hématologie-Immunologie Pédiatrique, Hôpital Robert Debré, Paris, France
| | - J Rivet
- Service d'Anatomopathologie, Hôpital Saint-Louis, Paris, France
| | - M Bagot
- Service de Dermatologie, AP-HP, Université Paris VII Sorbonne Paris Cité, Hôpital Saint-Louis, Paris, France
| | - J-H Dalle
- Service d'Hématologie-Immunologie Pédiatrique, Hôpital Robert Debré, Paris, France
| | - J-D Bouaziz
- Service de Dermatologie, AP-HP, Université Paris VII Sorbonne Paris Cité, Hôpital Saint-Louis, Paris, France
| |
Collapse
|
5
|
Haber R, Baroudjian B, Battistella M, Bagot M, Petit A. [Apparent worsening of psoriasis lesions revealing methotrexate overdosage]. Ann Dermatol Venereol 2017; 145:104-108. [PMID: 28917574 DOI: 10.1016/j.annder.2017.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 06/04/2017] [Accepted: 07/21/2017] [Indexed: 10/18/2022]
Abstract
BACKGROUND Methotrexate (MTX) is an antimetabolite drug used in the treatment of cancers and autoimmune diseases and frequently in dermatology for cutaneous and/or arthritic psoriasis. Toxicities due to MTX overdosage are mainly cutaneous, hepatic and hematologic. Herein, we report a case of MTX overdosage presenting as an erosive and an inflammatory flare of preexisting psoriatic plaques and with new palmar lesions. PATIENTS AND METHODS A 51-year-old male with a 6-year history of plaque psoriasis resistant to topical corticosteroids was started for the first time on MTX 20mg weekly. One week later, he presented with fever, general weakness and mucocutaneous ulcerations. Physical examination revealed inflammatory, erythematous and partially erosive annular plaques strictly confined to preexisting psoriatic lesions, along with keratotic psoriatic palmar plaques. Further questioning indicated that the patient was taking MTX 20mg daily. Investigations revealed neutropenia (1040/mm3) and skin histology showed prominent dystrophic keratinocytes and confirmed the diagnosis of methotrexate toxicity. Clinical and biological improvements were observed after cessation of MTX and treatment with folinic acid, IV hydration and urine alkalization. DISCUSSION Skin lesions due to acute MTX toxicity are rare, but they herald later-onset pancytopenia. Identification of these cutaneous lesions might enable earlier treatment initiation. The predilection of MTX toxicity for preexisting lesions or the de novo appearance of palmoplantar pustules should not lead to the erroneous diagnosis of psoriasis flare.
Collapse
Affiliation(s)
- R Haber
- Service de dermatologie, St George Hospital University Medical Center, Beirut, Liban.
| | - B Baroudjian
- Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France
| | - M Battistella
- Service de pathologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France
| | - M Bagot
- Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France
| | - A Petit
- Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France
| |
Collapse
|
6
|
|
7
|
Haber R, Maatouk I, De Barbeyrac B, Bagot M, Janier M, Fouere S. LGV très inflammatoires : le génotype L2b de Chlamydia trachomatis est-il plus virulent ? Ann Dermatol Venereol 2016. [DOI: 10.1016/j.annder.2016.09.492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
8
|
Haber R, Battistella M, Pages C, Bagot M, Lebbe C, Basset-Seguin N. Carcinomes sébacés cutanés : étude de 24 cas et revue de la littérature. Ann Dermatol Venereol 2016. [DOI: 10.1016/j.annder.2016.09.223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
9
|
Affiliation(s)
- R. Haber
- Department of Dermatology; Hotel Dieu de France University Hospital; Beirut Lebanon
- Faculty of Medicine; Saint Joseph University; Beirut Lebanon
| | - F. Stéphan
- Department of Dermatology; Hotel Dieu de France University Hospital; Beirut Lebanon
- Faculty of Medicine; Saint Joseph University; Beirut Lebanon
| |
Collapse
|
10
|
Kechichian E, Mourad N, Haber R, Elkhoury R, Tomb R. F9 : Premier cas de syndrome de Maffucci associé à des nevi épidermiques multiples. Ann Dermatol Venereol 2016. [DOI: 10.1016/s0151-9638(16)30116-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
11
|
El Khoury R, Kechichian E, Mourad N, Haber R, Tomb R, Maalouf E. F8 : Ichtyose linéaire circonflexe précoce dans le cadre d’un syndrome de Netherton. Ann Dermatol Venereol 2016. [DOI: 10.1016/s0151-9638(16)30115-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
12
|
Rossiter JA, Haber R, Zabet K. Pole-placement Predictive Functional Control for over-damped systems with real poles. ISA Trans 2016; 61:229-239. [PMID: 26723844 DOI: 10.1016/j.isatra.2015.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 12/01/2015] [Accepted: 12/04/2015] [Indexed: 06/05/2023]
Abstract
This paper gives new insight and design proposals for Predictive Functional Control (PFC) algorithms. Common practice and indeed a requirement of PFC is to select a coincidence horizon greater than one for high-order systems and for the link between the design parameters and the desired dynamic to be weak. Here the proposal is to use parallel first-order models to form an independent prediction model and show that with these it is possible both to use a coincidence horizon of one and moreover to obtain precisely the desired closed-loop dynamics. It is shown through analysis that the use of a coincidence horizon of one greatly simplifies coding, tuning, constraint handling and implementation. The paper derives the key results for high-order and non-minimum phase processes and also demonstrates the flexibility and potential industrial utility of the proposal.
Collapse
Affiliation(s)
- J A Rossiter
- Department of Automatic Control and Systems Engineering, University of Sheffield, S1 3JD, UK.
| | - R Haber
- University of Applied Science Cologne, Department of Plant and Process Engineering, D-50679 Kln, Betzdorfer Str. 2, Germany.
| | - K Zabet
- University of Applied Science Cologne, Department of Plant and Process Engineering, D-50679 Kln, Betzdorfer Str. 2, Germany
| |
Collapse
|
13
|
Haber R, Farid S. [Granulomatous tattoo reaction confined to red pigment]. Ann Dermatol Venereol 2015; 143:79-80. [PMID: 26640082 DOI: 10.1016/j.annder.2015.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 07/27/2015] [Accepted: 09/08/2015] [Indexed: 11/27/2022]
Affiliation(s)
- R Haber
- Département de dermatologie, hôpital Hôtel-Dieu de France, centre hospitalier, Beyrouth, Liban; Faculté de médecine, université Saint-Joseph, rue Alfred-Naccache, Achrafieh, Beyrouth, Liban.
| | - S Farid
- Département de dermatologie, hôpital Hôtel-Dieu de France, centre hospitalier, Beyrouth, Liban; Faculté de médecine, université Saint-Joseph, rue Alfred-Naccache, Achrafieh, Beyrouth, Liban
| |
Collapse
|
14
|
Haber R, Stephan F, Kamar F, Tomb R. Syndrome of inappropriate secretion of antidiuretic hormone in a patient with drug-induced hypersensitivity syndrome. J Eur Acad Dermatol Venereol 2015; 30:869-71. [DOI: 10.1111/jdv.13037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- R. Haber
- Department of Dermatology; Hotel Dieu de France University Hospital; Beirut Lebanon
- Faculty of Medicine; Saint Joseph University; Beirut Lebanon
| | - F. Stephan
- Department of Dermatology; Hotel Dieu de France University Hospital; Beirut Lebanon
- Faculty of Medicine; Saint Joseph University; Beirut Lebanon
| | - F. Kamar
- Department of Oncology; Belle-Vue Medical Center; Beirut Lebanon
| | - R. Tomb
- Department of Dermatology; Hotel Dieu de France University Hospital; Beirut Lebanon
- Faculty of Medicine; Saint Joseph University; Beirut Lebanon
| |
Collapse
|
15
|
Haber R. Buchbesprechung: Nonlinear Dynamics of Production Systems. Von G. Radons, R. Neugebauer. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.200490424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
16
|
|
17
|
Haber R, Grotberg JB, Glucksberg MR, Miserocchi G, Venturoli D, Del Fabbro M, Waters CM. Steady-state pleural fluid flow and pressure and the effects of lung buoyancy. J Biomech Eng 2001; 123:485-92. [PMID: 11601734 DOI: 10.1115/1.1392317] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Both theoretical and experimental studies of pleural fluid dynamics and lung buoyancy during steady-state, apneic conditions are presented. The theory shows that steady-state, top-to-bottom pleural-liquid flow creates a pressure distribution that opposes lung buoyancy. These two forces may balance, permitting dynamic lung floating, but when they do not, pleural-pleural contact is required. The animal experiments examine pleural-liquid pressure distributions in response to simulated reduced gravity, achieved by lung inflation with perfluorocarbon liquid as compared to air. The resulting decrease in lung buoyancy modifies the force balance in the pleural fluid, which is reflected in its vertical pressure gradient. The data and model show that the decrease in buoyancy with perfluorocarbon inflation causes the vertical pressure gradient to approach hydrostatic. In the microgravity analogue, the pleural pressures would be toward a more uniform distribution, consistent with ventilation studies during space flight. The pleural liquid turnover predicted by the model is computed and found to be comparable to experimental values from the literature. The model provides the flow field, which can be used to develop a full transport theory for molecular and cellular constituents that are found in pleural fluid.
Collapse
Affiliation(s)
- R Haber
- Biomedical Engineering Department, University of Michigan, Ann Arbor 48109, USA
| | | | | | | | | | | | | |
Collapse
|
18
|
Affiliation(s)
- R Villanueva
- Mount Sinai School of Medicine, New York, NY 10029, USA.
| | | |
Collapse
|
19
|
Bernstein RM, Rassman WR, Seager D, Shapiro R, Cooley JE, Norwood OT, Stough DB, Beehner M, Arnold J, Limmer BL, Avram MR, McClellan RE, Rose PT, Blugerman G, Gandelman M, Cotterill PC, Haber R, Jones R, Vogel JE, Moy RL, Unger WP. Standardizing the classification and description of follicular unit transplantation and mini-micrografting techniques. The American Society for Dermatologic Surgery, Inc. Dermatol Surg 1998; 24:957-63. [PMID: 9754083 DOI: 10.1111/j.1524-4725.1998.tb04288.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous attempts at classifying small graft transplants have focused mainly upon graft size and have not taken into consideration other technical factors involved in graft production that may influence the outcome of the surgery. The proposed classification attempts to consider these factors by including various technical aspects of harvesting, dissection, and placement, all of which impact the quality and quantity of the small grafts used in the procedure. By standardizing the nomenclature, as well as the description of the other factors involved in the surgery, communication between physicians and patients may be facilitated. In addition, different procedures may be more accurately studied and compared.
Collapse
|
20
|
|
21
|
Lyketsos CG, Storch DD, Lann HD, Finn R, Haber R, Meng R. HIV infection in Maryland public psychiatric facilities: results of an informal survey. Md Med J 1993; 42:571-3. [PMID: 8377630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The Maryland Psychiatric Society (MPS) Public Psychiatry Committee, concerned with the preparedness of Baltimore mental health facilities to deal with the accelerating human immunodeficiency virus (HIV) epidemic, surveyed public sector mental health facilities. The survey results indicated that the number of HIV-infected patients is greatly underestimated. Care providers acknowledged awareness of the problem and wanted more education.
Collapse
Affiliation(s)
- C G Lyketsos
- AIDS Psychiatry Service, Johns Hopkins University
| | | | | | | | | | | |
Collapse
|
22
|
Abstract
The gene for tryptophan 2,3-dioxygenase (TDO) heretofore was believed to be expressed only in liver. The data presented here demonstrate that RNA encoding TDO is present in rodent brain. Oligonucleotide primers based on the rat liver TDO cDNA sequence were synthesized and used to amplify RNA derived from mouse whole brain and liver and rat brain regions by the RNA-PCR. Reaction products were purified and subjected to DNA sequencing. Identical sequences were obtained when mouse whole brain and liver RNAs were amplified, and these sequences were shown to be 96% identical to the published rat liver tryptophan TDO cDNA sequence. In addition, TDO sequences were found in RNA derived from rat brainstem, cerebellum, cortex, hypothalamus, and the remainder of the brain.
Collapse
Affiliation(s)
- R Haber
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892
| | | | | | | | | |
Collapse
|
23
|
Abstract
The mRNA that encodes a serotonin transporter was expressed using the Xenopus laevis oocyte expression system. Poly(A)+ RNA isolated from mouse brainstem was injected into Xenopus laevis oocytes, and the ability of oocytes to take up serotonin was measured 3 days postinjection. RNA-dependent serotonin uptake was sensitive to citalopram, a specific inhibitor of serotonin uptake, whereas background levels of serotonin uptake were not citalopram sensitive. Two RNA size fractions, 4.0 and 4.5 kb, were most efficient in stimulating uptake. Injection into Xenopus laevis oocytes of the 4.5-kb size fraction of mouse brainstem RNA resulted in threefold more serotonin uptake than did injection of unfractionated poly(A)+ RNA.
Collapse
Affiliation(s)
- R Haber
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland 20892
| | | |
Collapse
|
24
|
Abstract
Factors related to hospital resource use by intensive care unit (ICU) patients, including severity of illness at admission and intensity of therapy during the first 24 ICU hours were explored in this study. Analysis was based on 2,749 patients admitted to the general medical-surgical ICU at Baystate Medical Center, Springfield, Massachusetts, between February 1, 1983 and January 10, 1985. Resource use was indexed by hospital length of stay (LOS) adjusted for differences between ICU and other hospital days. Severity of illness was measured by the Mortality Prediction Model (MPM0), a validated predictor of outcome but not previously used to analyze resource consumption. Intensity of therapy was measured using the Therapeutic Intervention Scoring System (TISS). The 10% of patients with longest ICU stays were significantly different from the other 90% with respect to previous ICU use, MPM probability, and TISS score. Variability in resource use was analyzed using four diagnosis-related groups (DRGs) accounting for large numbers of ICU patients. The relationship between severity of illness and resource was nonlinear: as severity increased from low levels, resource use increased at a decreasing rate, reached a plateau, and eventually declined. Within each DRG, MPM0 explained a statistically significant percentage of the variability in resource use.
Collapse
Affiliation(s)
- J Rapoport
- Department of Economics, Mount Holyoke College, South Hadley, MA
| | | | | | | | | |
Collapse
|
25
|
Abstract
Communication between distant DNA sites is a central feature of many DNA transactions. Negative regulation of the galactose (gal) operon of Escherichia coli requires repressor binding to two operator sites located on opposite sides of the promoter. The proposed mechanism for regulation involves binding of the repressor to both operator sites, followed by a protein-protein association that loops the intervening promoter DNA (double occupancy plus association). To assess these requirements in vivo, we have previously converted gal operator sites to lac and shown that both operator sites must be occupied by the homologous repressor protein (Lac or Gal) for negative regulation of the gal operon. We have now addressed more directly the need for protein-protein association by the use of the converted operator sites and a mutant Lac repressor defective in association of the DNA-binding dimers. We have compared the biological and biochemical activity of two Lac repressors: the wild-type (tetramer) I+ form, in which the DNA-binding dimer units are tightly associated; and the mutant Iadi repressor, in which the dimer units do not associate effectively. The I+ repressor is an efficient negative regulator of the gal operon in vivo, but the Iadi mutant is an ineffective repressor. Purified I+ repressor efficiently forms DNA loops between operator sites that we have visualized by electron microscopy; the Iadi repressor fails to form DNA loops, although the protein binds effectively to both operator sites. From the clear correlation between looping in vitro and repression in vivo, we conclude that regulation of the gal operon depends on the association of repressor proteins bound to the two operator sites.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- N Mandal
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | | | | | | | | |
Collapse
|
26
|
Abstract
Two operators, spatially separated from each other and from the promoters, repress the gal operon when bound to Gal repressor. Conversion of either gal operator to a lac operator results in derepression, although both Gal and Lac repressors are present, suggesting that mere occupation of operator sites is not sufficient to cause repression. Conversion of both operators to lac operators restores normal repression in the presence of Lac repressor protein. We propose that normal repression requires interaction between operator-bound like repressor molecules; this generates a DNA loop, which is part of a higher order structure. RNA polymerase and cyclic AMP receptor protein are present in this complex but unable to initiate transcription because of the higher order structure. Such higher order DNA-multiprotein complexes could occur in a variety of genetic regulatory systems that are controlled from distal sites by regulatory proteins.
Collapse
Affiliation(s)
- R Haber
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, MD 20892
| | | |
Collapse
|
27
|
|
28
|
Tolstoshev P, Haber R, Trapnell BC, Crystal RG. Procollagen messenger RNA levels and activity and collagen synthesis during the fetal development of sheep lung, tendon, and skin. J Biol Chem 1981; 256:9672-9. [PMID: 7287703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The rates of type I collagen synthesis in sheep lung, tendon, and skin were evaluated during the latter half of fetal development and compared with the levels of type I procollagen mRNA, quantified by molecular hybridization with a type I procollagen specific complementary DNA, and with the activity of total procollagen mRNA measured by in vitro cell-free translation. In the lung and tendon, the levels of type I procollagen mRNA and activity of total procollagen mRNA parallel collagen synthesis during development. In the skin, however, type I collagen synthesis declines sharply during fetal development, but both type I procollagen mRNA levels and total procollagen mRNA activity remain at the high levels of early development. These observations suggest that in developing lung and tendon, type I procollagen mRNA levels are likely the major determinants of the levels of type I collagen synthesis. In contrast, the dichotomy between type I procollagen mRNA levels and rates of type I collagen synthesis in the developing sheep skin suggest the skin utilizes mechanisms in addition to mRNA levels to modulate expression of the type I collagen gene.
Collapse
|
29
|
Tolstoshev P, Haber R, Trapnell B, Crystal R. Procollagen messenger RNA levels and activity and collagen synthesis during the fetal development of sheep lung, tendon, and skin. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68815-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
30
|
Abstract
Caffeine (1,3,7-trimethylxanthine) is a biotransformation product of theophylline (1,3-dimethylxanthine) in the human fetus. Liver explants, obtained from human fetuses with gestational ages of 12 to 20 weeks, were incubated with theophylline and produced caffeine and, in lesser amounts, 1,3-dimethyluric acid and 3-methylxanthine. These findings suggest that the predominant pathway in theophylline metabolism in the fetus and newborn infant is the methylation reaction producing caffeine. This may contribute to the neonate's exceedingly slower elimination of caffeine relative to theophylline. Caffeine produced from theophylline may add to the pharmacologic effects of theophylline in newborn infants with apnea.
Collapse
|
31
|
Tolstoshev P, Haber R, Crystal RG. Procollagen alpha2 mRNA is significantly different from procollagen alpha1(I) mRNA in size or secondary structure. Biochem Biophys Res Commun 1979; 87:818-26. [PMID: 454429 DOI: 10.1016/0006-291x(79)92031-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
32
|
|