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1.
Braz J Med Biol Res ; 56: e12521, 2023.
Article in English | MEDLINE | ID: mdl-37194833

ABSTRACT

Congenital diaphragmatic hernia (CDH) is associated with thoracic compression of the lungs and heart caused by the herniated abdominal content, leading to cardiac modifications including pressure and vascular changes. Our aim was to investigate the experimental immunoexpression of the capillary proliferation, activation, and density of Ki-67, VEGFR2, and lectin in the myocardium after surgical creation of a diaphragmatic defect. Pregnant New Zealand rabbits were operated on the 25th gestational day in order to create left-sided CDH (LCDH, n=9), right-sided CDH (RCDH, n=9), and Control (n=9), for a total of 27 fetuses in 19 pregnant rabbits. Five days after the procedure, animals were sacrificed, and histology and immunohistochemistry studies of the harvested hearts were performed. Total body weight and heart weight were not significantly different among groups (P=0.702 and 0.165, respectively). VEGFR2 expression was increased in both ventricles in the RCDH group (P<0.0001), and Ki-67 immunoexpression was increased in the left ventricle in the LCDH group compared to Control and RCDH groups (P<0.0001). In contrast, capillary density was reduced in the left ventricle in the LCDH compared to the Control and RCDH groups (P=0.002). Left and right ventricles responded differently to CDH in this model depending on the laterality of the diaphragmatic defect. This surgical model of diaphragmatic hernia was associated with different expression patterns of capillary proliferation, activation, and density in the myocardium of the ventricles of newborn rabbits.


Subject(s)
Hernias, Diaphragmatic, Congenital , Pregnancy , Female , Rabbits , Animals , Hernias, Diaphragmatic, Congenital/complications , Hernias, Diaphragmatic, Congenital/pathology , Ki-67 Antigen , Lung/pathology , Myocardium , Fetus
2.
Braz. j. med. biol. res ; 56: e12521, 2023. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1439709

ABSTRACT

Congenital diaphragmatic hernia (CDH) is associated with thoracic compression of the lungs and heart caused by the herniated abdominal content, leading to cardiac modifications including pressure and vascular changes. Our aim was to investigate the experimental immunoexpression of the capillary proliferation, activation, and density of Ki-67, VEGFR2, and lectin in the myocardium after surgical creation of a diaphragmatic defect. Pregnant New Zealand rabbits were operated on the 25th gestational day in order to create left-sided CDH (LCDH, n=9), right-sided CDH (RCDH, n=9), and Control (n=9), for a total of 27 fetuses in 19 pregnant rabbits. Five days after the procedure, animals were sacrificed, and histology and immunohistochemistry studies of the harvested hearts were performed. Total body weight and heart weight were not significantly different among groups (P=0.702 and 0.165, respectively). VEGFR2 expression was increased in both ventricles in the RCDH group (P<0.0001), and Ki-67 immunoexpression was increased in the left ventricle in the LCDH group compared to Control and RCDH groups (P<0.0001). In contrast, capillary density was reduced in the left ventricle in the LCDH compared to the Control and RCDH groups (P=0.002). Left and right ventricles responded differently to CDH in this model depending on the laterality of the diaphragmatic defect. This surgical model of diaphragmatic hernia was associated with different expression patterns of capillary proliferation, activation, and density in the myocardium of the ventricles of newborn rabbits.

3.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 241-251, 2021.
Article in English | MEDLINE | ID: mdl-34281322

ABSTRACT

The research is aiming to obtain at room temperature a new ceramic material containing partially stabilized zirconia with different oxides after sintering used for dental and other technological purposes. Our research proposes a new method based on the use of stabilized zirconia with other oxides to obtain optimized dental material with a lower cost price and / or improved properties to allow wider use of these products to an increased number of patients in dental offices. X-ray diffraction, SEM analysis. FTIR spectroscopy, UVVis and density measurements were accomplished for the three ceramic systems. The correlation between the microstructure and the spectroscopic properties of zirconium stabilized by FTIR spectroscopy, UV-Vis helps understanding the mechanisms associated with the formation of high (tetragonal and / or cubic) temperature zirconia. Along with the simple, less costly preparation method and high purity of the ceramic products our study offers a highly desirable product for technological applications.


Subject(s)
Ceramics , Zirconium , Humans , Materials Testing , Surface Properties , X-Ray Diffraction
4.
Rehabilitacion (Madr) ; 54(1): 3-10, 2020.
Article in Spanish | MEDLINE | ID: mdl-32007180

ABSTRACT

OBJECTIVE: The main aim of this study was to assess the efficacy of percutaneous posterior tibial nerve electrostimulation (P-PTNS) in urge urinary incontinence (UUI) and faecal incontinence (FI) refractory to first-line treatment. A secondary aim was to identify predictors of treatment response. To do this, we performed a 2-year analytical, longitudinal and prospective study in patients with UUI and FI treated with P-PTNS. MATERIAL AND METHODS: We included patients with UUI and FI who were treated with P-PTNS and who completed the bladder/faecal incontinence diary and severity and quality of life questionnaires. We excluded patients with neurogenic UUI and those who abandoned treatment or did not complete the questionnaires. We assessed demographic and clinical variables (micturition/defecation habits pre- and postreatment), severity scales before and after treatment (ICIQ-SF, Sandvick and Wexner), subjective improvement and quality of life (IQOL and FIQL pre- and postreatment). The statistical analysis was conducted using SPSS v19. RESULTS: The sample consisted of 21 patients divided into 2 groups: -UUI group, 9 patients. After P-PTNS, there was a statistically significant improvement in diurnal (p=.018) and nocturnal (p=.016) urinary frequency, urgencies/day (p=.018), urine leakage/day (p=.027), ICIQ-SF and Sandvick (p=.018), and IQOL (p=.012). This improvement was related to exercise (p=.039) and prolapse (p=.05). -Group FI, 12 patients. After P-PTNS, there was a statistically significant improvement in defecation frequency (p=.027), incontinence (p=.012), Wexner scale (p=.007), and FIQL in its 4 dimensions (lifestyle, behaviour, embarrassment p=.005; and depression p=.008). This improvement was related to age (p=.048), time since onset (p=.044) and prolapse (p=.026). CONCLUSIONS: The P-PTNS is effective in UUI and FI refractory to conventional treatment. Treatment response is affected by several factors.


Subject(s)
Electric Stimulation Therapy/methods , Fecal Incontinence/therapy , Quality of Life , Tibial Nerve , Urinary Incontinence, Urge/therapy , Age Factors , Aged , Fecal Incontinence/physiopathology , Female , Health Surveys , Humans , Male , Middle Aged , Prospective Studies , Severity of Illness Index , Sex Factors , Time Factors , Treatment Outcome , Urinary Incontinence, Urge/physiopathology
5.
Rehabilitacion (Madr) ; 53(1): 13-19, 2019.
Article in Spanish | MEDLINE | ID: mdl-30929827

ABSTRACT

INTRODUCTION: To evaluate the effectiveness of early capsular ultrasound-guided hydrodilatation (HD) of the proximal interphalangeal or metacarpophalangeal joints in reducing joint stiffness and shortening kinesitherapy, as well as in improving hand functionality. MATERIAL AND METHODS: We performed a one-year quasi-experimental pretest-posttest study with a control group in patients with proximal interphalangeal or metacarpophalangeal capsulitis in complex regional pain syndrome stages 2 or 3. Inclusion criteria consisted of age over 18 years, visual analogue scale<4 points and the absence of prior treatment. The control group received only kinesitherapy and the experimental group received capsular HD before kinesitherapy. There were 10 patients per group. The main measures were range of motion, active grip, Spanish validated Michigan Hand Outcomes Questionnaire and the number of kinesitherapy sessions required. RESULTS: At baseline, the range of motion of the proximal proximal interphalangeal joint was 20° worse in the experimental group (P=.01). There were no statistically significant differences in the other baseline characteristics. Immediate gain in range of motion after HD was 61.71% (P=.024). No significant improvements were observed in functionality except in active grip after 2 weeks of HD (P=.02) and one month later compared with the control group (P=.014). The number of kinesitherapy sessions required was 19.6±10.42 (95% CI) in the HD group and 29.4±8.11 (95% CI) in the control group (P>.05). CONCLUSIONS: Capsular HD could be considered as an initial treatment in finger joint stiffness because of the significant immediate improvement in range of motion. It is also an innovative technique in these joints with a short learning curve. The technique can be safely and effectively performed in a physiatry consulting room.


Subject(s)
Bursitis/therapy , Dilatation/methods , Exercise Therapy/methods , Female , Finger Joint/pathology , Humans , Male , Metacarpophalangeal Joint/pathology , Range of Motion, Articular , Treatment Outcome , Ultrasonography, Interventional
6.
J Neuroimmune Pharmacol ; 14(3): 413-422, 2019 09.
Article in English | MEDLINE | ID: mdl-30649665

ABSTRACT

Analysis of gut barrier status, monocyte and lymphocyte activation and T regulatory (Treg) cells at diagnosis before and after therapy, in patients with multiple sclerosis (MS). Analysis of differential effects of interferon beta (IFN-ß), glatiramer acetate (GA) and natalizumab. Thirty-five patients with untreated MS were included. Gut barrier status (serum concentrations of intestinal fatty acid binding protein), monocyte (serum levels of soluble CD14, soluble CD163 and interleukin 6) and T lymphocyte activation (CD4 + DR+ and CD8 + DR+) and Treg (CD4 + CD25highFoxP3+) cells were analyzed. Patients with clinical isolated syndrome and relapsing-remitting forms were treated with IFN-ß or GA, and immune characteristics were reevaluated following up after 6 months. A sample of 56 stable RR MS patients, in treatment with IFN-ß, GA or natalizumab, and 50 healthy individuals were included as controls. Gut barrier status was similar in MS patients and healthy controls. Untreated patients with relapsing-remitting and primary progressive patterns of MS showed increased serum levels of soluble CD14. At baseline, significant increases in activated T lymphocytes and Treg were detected in patients. A significant decrease of CD4 + DR+, CD8 + DR+, and Treg percentages after 6 months of therapy was observed. In previously treated patients, IFN-ß, GA, or natalizumab therapies were associated with a comparable cell proportion of activated lymphocytes and Treg. MS patients have a baseline state characterized by monocyte and lymphocyte activation, not related with gut barrier lesion. An increase in Treg number, correlated with activated T CD8+ lymphocytes, was detected. Treatment with IFN-ß, GA or natalizumab was associated with a comparable decrease in activated lymphocytes and Treg. Graphical Abstract ᅟ.


Subject(s)
Glatiramer Acetate/pharmacology , Interferon-beta/pharmacology , Lymphocyte Activation/drug effects , Monocytes/drug effects , Multiple Sclerosis, Chronic Progressive/drug therapy , Multiple Sclerosis, Relapsing-Remitting/drug therapy , Natalizumab/pharmacology , T-Lymphocyte Subsets/drug effects , Adult , Case-Control Studies , Fatty Acid-Binding Proteins/blood , Female , Gene Expression Regulation/drug effects , Glatiramer Acetate/therapeutic use , Humans , Interferon-beta/therapeutic use , Male , Middle Aged , Monocytes/immunology , Monocytes/metabolism , Multiple Sclerosis/drug therapy , Multiple Sclerosis, Chronic Progressive/immunology , Multiple Sclerosis, Relapsing-Remitting/immunology , NF-kappa B/metabolism , Natalizumab/therapeutic use , Nerve Tissue Proteins/biosynthesis , Nerve Tissue Proteins/genetics , Prospective Studies , Signal Transduction/drug effects , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism
7.
Rev Esp Cir Ortop Traumatol ; 60(5): 306-14, 2016.
Article in English, Spanish | MEDLINE | ID: mdl-27435988

ABSTRACT

INTRODUCTION: Only a few clinical exploratory manoeuvres are truly discriminatory and useful in shoulder disease. The aim of this study is to correlate the physical examination results of the shoulder with the true diagnosis found by arthroscopy. METHODS: A retrospective case series of 150 patients with the most common surgical conditions of the shoulder. Data were collected on the suspicion of each pathology, the physical examination of the patient, and the actual discovery of the disease during arthroscopic surgery. RESULTS: The Bankart examination manoeuvres of the lesion show the best results, with a 92.1% positive prediction value (PPV), a 99.1% negative predictive value (NPV), followed by the impingement syndrome, with a PPV of 94.4%, and total cuff rupture with a PPV of 92.3%.Exploration of the superior labrum anterior to posterior (SLAP) lesion had an NPV of 99.1%. CONCLUSION: Physical examination is sufficient to diagnose or rule out Bankart. A positive physical examination provides the complete rupture of the rotator cuff, and requires further studies. The patients suspected of subacromial syndrome only need an NMR if the physical tests are negative. The conclusions drawn from this work can have a significant impact on both cost savings (by reducing forward tests), and saving time in certain cases in which, after appropriate physical examination, surgery may be indicated without losing time in intermediate steps.


Subject(s)
Arthroscopy , Joint Diseases/diagnosis , Physical Examination , Shoulder Injuries/diagnosis , Shoulder Joint/surgery , Adult , Aged , Aged, 80 and over , Female , Humans , Joint Diseases/surgery , Longitudinal Studies , Male , Middle Aged , Predictive Value of Tests , Retrospective Studies , Shoulder Injuries/surgery
8.
Metab Brain Dis ; 31(6): 1239-1247, 2016 12.
Article in English | MEDLINE | ID: mdl-26497651

ABSTRACT

Central Nervous System (CNS) degeneration appearing in patients with cirrhosis is responsible for cognitive and persistent motor impairments that lead to an important impact on life quality. Brain injury affects certain areas of the CNS that might affect two types of cells: neurons and astrocytes. The process leading to brain injury could be induced by portosystemic shunting accompanied by hyperammonemia and by the activation of peripheral inflammation, manifested as episodic encephalopathy. Hyperammonemia combined with a decrease on the BCA/AAA ratio induces alterations of energetic metabolism and the formation of free radicals in the CNS. This process would be stimulated by the activation of peripheral inflammatory mediators that could act on receptors of the blood brain barrier such as TLR4, activating inflammatory responses in the CNS. As a result, a persistent activation of microglia and an irreversible neuronal and astrocytic injury would be induced. A new knowledge of the mechanisms leading to brain injury in cirrhosis would develop protective strategies to correct changes of nitrogen metabolism and inflammation.


Subject(s)
Hepatic Encephalopathy/metabolism , Hepatic Encephalopathy/pathology , Inflammation Mediators/metabolism , Animals , Astrocytes/metabolism , Astrocytes/pathology , Blood-Brain Barrier/metabolism , Blood-Brain Barrier/pathology , Brain/metabolism , Brain/pathology , Hepatic Encephalopathy/therapy , Humans , Inflammation/metabolism , Inflammation/pathology , Inflammation/therapy
9.
Rehabilitación (Madr., Ed. impr.) ; 49(1): 10-16, ene.-mar. 2015. tab, ilus
Article in Spanish | IBECS | ID: ibc-132950

ABSTRACT

Introducción. La enfermedad pulmonar obstructiva crónica (EPOC) constituye una patología de gran impacto en nuestra sociedad siendo la disnea el síntoma principal. Los programas de rehabilitación respiratoria pretenden disminuir la morbimortalidad y aumentar la calidad de vida. Nuestro objetivo es analizar la efectividad a largo plazo de un programa de rehabilitación respiratoria en cuanto a calidad de vida, adherencia al tratamiento y morbimortalidad. Material y métodos. Estudio observacional transversal sobre una cohorte prospectiva. Incluye a pacientes con EPOC grado III y IV de GOLD estabilizados que han completado el programa de rehabilitación respiratoria. Se diseña un cuestionario recogiendo percepción de disnea, aparición de exacerbaciones, mortalidad, adherencia al tratamiento y calidad de vida medidas con los cuestionarios ansiedad-depresión, Saint George Respiratory Questionnaire (SGRQ) y Chronic Respiratory Questionary (CRQ) al inicio y al año del tratamiento. Resultados. Se aprecia disminución de la percepción de disnea al mes del tratamiento. La media del número de exacerbaciones fue 4,06 y el porcentaje de mortalidad del 5,9% al año de tratamiento. Un 78,9% de pacientes continuaron el entrenamiento domiciliario, obteniéndose mejores resultados al realizarlo más de 3 días en semana. La media de la mejoría de calidad de vida fue positiva en los cuestionarios ansiedad/depresión, en la escala SGRQ y en algunas áreas de la escala CRQ. Conclusiones. La intervención sanitaria centrada en un programa de rehabilitación respiratoria es útil a largo plazo para el beneficio en salud, observándose una mejoría en la autonomía para las actividades de la vida diaria y en la autopercepción de calidad de vida (AU)


Introduction. Chronic obstructive pulmonary disease (COPD) has a huge impact in Spain. The main symptom is dyspnea. Pulmonary rehabilitation aims to decrease morbidity and mortality and increase quality of life. The aim of our study was to assess the long-term effectiveness of a respiratory rehabilitation program in enhancing quality of life and treatment adherence and in reducing mortality and morbidity. Material and methods. A cross-sectional observational study was carried out in a prospective cohort of patients with stable grade III and IV COPD, as measured by the GOLD scale. The participants completed a pulmonary rehabilitation program. A questionnaire was designed to collect perceptions of dyspnea, exacerbations, mortality, treatment adherence, and quality of life, measured with anxiety-depression questionnaires, the Saint George Respiratory Questionnaire (SGRQ) and the Chronic Respiratory Questionnaire (CRQ) before and 1 year after of treatment. Results. The perception of dyspnea decreased after a month of treatment. At 1 year, the number of exacerbations was 4.06 and mortality was 5.9%. A total of 78.9% of the patients continued training at home and obtained better results if they trained 3 days per week or more. Quality of life showed improvement in the anxiety-depression questionnaires, SGRQ scale, and in some areas of the CRQ scale. Conclusions. The pulmonary rehabilitation program produced long-term benefits for health, improving autonomy in activities of daily living and self-perceived quality of life (AU)


Subject(s)
Humans , Male , Female , Pulmonary Disease, Chronic Obstructive/prevention & control , Pulmonary Disease, Chronic Obstructive/rehabilitation , Treatment Outcome , Rehabilitation Services , Evaluation of Results of Therapeutic Interventions/trends , /methods , Quality of Life , Cross-Sectional Studies , Cohort Studies , Surveys and Questionnaires , Analysis of Variance
10.
Water Sci Technol ; 70(7): 1143-51, 2014.
Article in English | MEDLINE | ID: mdl-25325537

ABSTRACT

The performance assessment of storage tanks and combined sewer overflow (CSO) structures in sewer systems requires knowledge of the total inflow from the catchment during rainfall events. Many structures are, however, only equipped with sensors to measure water level and/or outflows. Based on the geometry of the tank, expressed as a level-storage relationship, inflow can be calculated from these data using a simple conceptual storage model. This paper compares a deterministic and a Bayesian approach for estimating the inflow to a CSO structure from measurements of outflows and water level. The Bayesian approach clearly outperforms the deterministic estimation which is very sensitive to measurement errors. Although computationally more demanding, the use of a simple linear storage model allows the online application of the Bayesian approach to repeatedly estimate inflow in short time intervals of a few minutes. The method could thus be used as an online software sensor for inflow to storage structures in sewer systems.

12.
Sanid. mil ; 68(4): 231-233, oct.-dic. 2012. ilus
Article in Spanish | IBECS | ID: ibc-109684

ABSTRACT

Presentamos el caso de una paciente de 47 años de edad que consulta en urgencias por un cuadro de 8 horas de evolución, de dolor abdominal continuo y difuso, acompañado de vómitos alimentarios al inicio y biliosos después. La paciente presenta estabilidad hemodinámica permaneciendo afebril. El hemiabdomen inferior presenta signos de irritación peritoneal. En los análisis destaca la presencia de neutrofilia y leucocitosis, la radiología simple de abdomen es compatible con suboclusión de intestino delgado, y la TAC de urgencia sugiere la posibilidad de torsión intestinal. La cirugía urgente realizada aprecia una hernia interna de un segmento de ileon de unos 25cm, a través de un orificio patológico en el lado derecho del ligamento ancho del útero. Se realiza resección del asa herniada que sufre necrosis isquémica y se cierra el orificio herniario para evitar la recidiva. El día 11 tras el ingreso, es dada de alta sin complicaciones (AU)


We present the case of a 47-year-old gravida 2, para 2, with previous 2 caesarean sections. The patient presented to our hospital with a chief complaint of diffuse continuous abdominal pain and vomiting. Her lower abdomen had tenderness and was slightly distended. The patient had no fever and was hemodynamically stable. The laboratory test showed an elevated white blood cell count with a left shift. Plain abdominal X-rays showed a lightly prominent small bowel loops in the left upper quadrant. CT scan suggests the possibility of intestinal torsion. At this stage, we elected to perform an urgent laparoscopic exploration. We discovered 25 cm of ileum strangulated through a defect in the right broad ligament of the uterus. Resection of the necrotic small bowel loop, and closure of the broad ligament were performed. The patient was discharged from the hospital on day 11, with no postoperative complications (AU)


Subject(s)
Humans , Female , Middle Aged , Hernia, Abdominal/complications , Intestinal Obstruction/etiology , Torsion Abnormality/complications , Laparoscopy , Abdomen, Acute
15.
Braz J Med Biol Res ; 43(3): 249-56, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20401432

ABSTRACT

A series of studies have shown that the heavy burdens of diarrheal diseases in the first 2 formative years of life in children living in urban shanty towns have negative effects on physical and cognitive development lasting into later childhood. We have shown that APOE4 is relatively common in shanty town children living in Brazil (13.4%) and suggest that APOE4 has a protective role in cognitive development as well as weight-for-height in children with heavy burdens of diarrhea in early childhood (64/123; 52%), despite being a marker for cognitive decline with Alzheimer's and cardiovascular diseases later in life. APOE2 frequency was higher among children with heaviest diarrhea burdens during the first 2 years of life, as detected by PCR using the restriction fragment length polymorphism method, raising the possibility that ApoE-cholesterol balance might be critical for growth and cognitive development under the stress of heavy diarrhea burdens and when an enriched fat diet is insufficient. These findings provide a potential explanation for the survival advantage in evolution of genes, which might raise cholesterol levels during heavy stress of diarrhea burdens and malnutrition early in life.


Subject(s)
Apolipoproteins E/genetics , Diarrhea, Infantile/genetics , Polymorphism, Genetic/genetics , Apolipoproteins E/metabolism , Brazil , Child Development , Child, Preschool , Cognition , Cohort Studies , Diarrhea, Infantile/complications , Diarrhea, Infantile/metabolism , Female , Gene Frequency , Genotype , Humans , Infant , Infant, Newborn , Male , Mouth Mucosa/cytology , Polymerase Chain Reaction , Socioeconomic Factors
16.
Braz. j. med. biol. res ; 43(3): 249-256, Mar. 2010. tab, graf
Article in English | LILACS | ID: lil-539712

ABSTRACT

A series of studies have shown that the heavy burdens of diarrheal diseases in the first 2 formative years of life in children living in urban shanty towns have negative effects on physical and cognitive development lasting into later childhood. We have shown that APOE4 is relatively common in shanty town children living in Brazil (13.4 percent) and suggest that APOE4 has a protective role in cognitive development as well as weight-for-height in children with heavy burdens of diarrhea in early childhood (64/123; 52 percent), despite being a marker for cognitive decline with Alzheimer’s and cardiovascular diseases later in life. APOE2 frequency was higher among children with heaviest diarrhea burdens during the first 2 years of life, as detected by PCR using the restriction fragment length polymorphism method, raising the possibility that ApoE-cholesterol balance might be critical for growth and cognitive development under the stress of heavy diarrhea burdens and when an enriched fat diet is insufficient. These findings provide a potential explanation for the survival advantage in evolution of genes, which might raise cholesterol levels during heavy stress of diarrhea burdens and malnutrition early in life.


Subject(s)
Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Apolipoproteins E/genetics , Diarrhea, Infantile/genetics , Polymorphism, Genetic/genetics , Apolipoproteins E/metabolism , Brazil , Child Development , Cognition , Cohort Studies , Diarrhea, Infantile/complications , Diarrhea, Infantile/metabolism , Gene Frequency , Genotype , Mouth Mucosa/cytology , Polymerase Chain Reaction , Socioeconomic Factors
17.
Opt Lett ; 32(13): 1869-71, 2007 Jul 01.
Article in English | MEDLINE | ID: mdl-17603597

ABSTRACT

We report on peculiar dynamic features of laser oscillation in a cavity with a semiconductor junction as the gain medium and an intracavity atomic absorber. The output face of the semiconductor is antireflection coated, and lasing action is achieved by using a diffraction grating to close the laser cavity. The spectral analysis of the laser emission evidences a stable emission with narrow linewidth when the oscillating frequency is resonant with the atomic absorber. We also observe frequency bistability and instability. The change between these regimes is controlled through the bias current in a very reproducible way.

18.
Opt Express ; 15(26): 17699-708, 2007 Dec 24.
Article in English | MEDLINE | ID: mdl-19551066

ABSTRACT

We report on a simple anisotropic magneto-optical trap for neutral atoms that produces a large sample of cold atoms confined in a cylindrically-shaped volume with a high aspect ratio (100:1). Due to the large number of trapped atoms, the laser beams that propagate along the optically thick axis of the trap to cool the atoms are substantially attenuated. We demonstrate that the resulting intensity imbalance produces a net force that spatially localizes the atoms. This limits both the trap length and the total number of trapped atoms. Rotating the cooling beams by a small angle relative to the trap axis avoids the problem of attenuation, and atoms can be trapped throughout the entire available trapping volume. Numerical and experimental results are reported that demonstrate the effects of absorption in an anisotropic trap, and a steady-state, line-center optical path length of 55 is measured for a probe beam propagating along the length of the trap.


Subject(s)
Magnetics/instrumentation , Optical Tweezers , Absorption , Anisotropy , Computer-Aided Design , Equipment Design , Equipment Failure Analysis , Light , Reproducibility of Results , Scattering, Radiation , Sensitivity and Specificity
19.
Phys Rev Lett ; 94(17): 173902, 2005 May 06.
Article in English | MEDLINE | ID: mdl-15904291

ABSTRACT

The emission frequency of a diode laser submitted to a frequency-dependent optoelectronic feedback is observed to have more than one stable operation point together with a stable power emission. This is, to our knowledge, the first observation of bistability exclusively in the frequency of an optical system. The experiment was carried out with a semiconductor laser coupled to the cesium D2 line by an orthogonally polarized frequency-sensitive optical feedback.

20.
Biometals ; 17(3): 203-8, 2004 Jun.
Article in English | MEDLINE | ID: mdl-15222466

ABSTRACT

The transferrin family of non-heme iron binding glycoproteins are believed to play a central role in iron metabolism and have been implicated in iron transport, cellular iron delivery and control of the level of free iron in external secretions. Lactoferrin (LF) is a member of this family that is widely localized in external fluids including milk and mucosal secretions, in addition to being a prominent component of the secondary granules of neutrophils. Although structurally related to transferrin, LF appears to have a broader functional role mediated by both iron dependent and iron independent mechanisms. In this review, we will focus on our current understanding on the role of LF in regulating iron homeostasis and its role in host protection against microbial infection at the mucosal surface. In addition, recent insights obtained from analyzing the phenotypic consequences of LF ablation in lactoferrin knockout mice (LFKO), which challenge the long held dogma that LF is required for intestinal iron absorption in the neonate, are summarized.


Subject(s)
Anti-Infective Agents/metabolism , Homeostasis , Iron/metabolism , Lactoferrin/metabolism , Animals , Humans , Lactoferrin/genetics , Milk, Human/chemistry , Mucous Membrane/chemistry , Mucous Membrane/metabolism
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