Effect of an aperture in atomic gravimetry.

There is a continuous interest in shrinking the dimensions of portable atomic gravimeters. This inevitably ends up truncating the Gaussian wings of the excitation laser beams whose effect has not been properly quantified yet. The diffraction pattern created from this aperture creates ripples in the wavefront in both the phase and the intensity. We calculate the shift in the measured value of an atomic gravimeter introduced by the phase variations in the wavefront. Fortunately, this shift has a Gaussian decay with the aperture size. For extended clouds, we observe a reduction of the effect thanks to an averaging over transverse positions with different values of the shift. Surprisingly, we found that the intensity variations also introduce an important correction to the photon recoil, which contributes at about the same level as the previous shift in the measurement of the gravitational acceleration. Our results should help decide how small an apparatus can be to guarantee a particular accuracy.

Efficacy of endoscopic removal in the treatment of subglottic ductal cysts. / Eficacia de la escisión endoscópica en el tratamiento de los quistes ductales subglóticos.

INTRODUCTION: Subglottic cyst is a rare cause of airway obstruction, and there is a lack of evidence about the best treatment in the literature. This report describes our experience with endoscopic removal. MATERIAL AND METHODS: A retrospective study of all patients undergoing endoscopic removal of subglottic cyst at our healthcare facility between 2014 and 2019 was performed. Clinic and demographic data regarding gestational age, intubation, comorbidities, surgical procedures, first symptoms, endoscopic findings, treatment, and follow-up were collected. RESULTS: Four patients were identified. Two out of four (50%) were preterm, and all patients were intubated during their neonatal period. Median age and weight at diagnosis were 6.5 months (6-8) and 5.9 kg (3.6-7). Median time between last intubation and diagnosis was 119.5 days (71-171). Biphasic stridor and progressive respiratory distress were the most common clinical symptoms. Airway obstruction of at least 50% was found during upper airway endoscopy in all patients. Endoscopic removal was performed as a first-line treatment in 3 patients, and as a second-line treatment in 1 patient. Median intubation time after treatment and hospital stay were 13.5 hours (0-48) and 7 days (6-9). All four patients are free of disease, with a median follow-up of 17.5 months (6-42). CONCLUSION: Subglottic cyst is a rare cause of post-extubation stridor. Endoscopic removal seems to be a feasible and effective treatment with a low recurrence rate.

INTRODUCCION: Los quistes ductales subglóticos adquiridos (QDSA) son una causa rara de obstrucción de la vía aérea, sin consenso en la literatura en cuanto al tratamiento más eficaz. Presentamos nuestra experiencia en el tratamiento de los QDSA. MATERIAL Y METODOS: Estudio retrospectivo de los pacientes tratados en nuestro centro por QDSA en los últimos 5 años. Se recogieron los antecedentes de intubación, la clínica presentada, el tratamiento realizado, la evolución postquirúrgica, el seguimiento en consulta y los controles endoscópicos. RESULTADOS: Se identificaron 4 pacientes, con unas medianas de edad y peso de 6,5 meses (6-8) y 5,9 kg (3,6-7), respectivamente. Todos presentaron antecedentes de intubación por intervenciones quirúrgicas, siendo prematuros 2 de ellos. La mediana entre la última intubación y el diagnóstico fue de 119,5 días (71-171). La clínica consistió en estridor bifásico con mejoría postural presentando una ocupación de la luz traqueal de más del 50% en la endoscopia diagnóstica. Se realizó escisión endoscópica (EE) al diagnóstico en 3 de los pacientes y como técnica de rescate en el cuarto por recidiva tras tratamiento con drenaje y dilatación con balón. La mediana de tiempo de intubación postquirúrgico fue de 13,5 horas (0-48) y la estancia hospitalaria de 7 días (6-9). Tras un seguimiento mediano de 17,5 meses (6-42) no se ha presentado ninguna recidiva. CONCLUSION: Los QDSA son una causa poco frecuente de estridor post-extubación. La EE permite un tratamiento eficaz con baja tasa de recidiva.

[Intussusception: hospital admission for risk of recurrence or early discharge?] / Invaginación intestinal: ¿alta precoz o ingreso por riesgo de recidiva?

INTRODUCTION/PURPOSE: There is current debate about the need of hospitalization of patients with enema-reduced intussusception. The purpose of this study is to describe intussusception recurrence in a tertiary care children's hospital in order to evaluate the feasibility of ambulatory treatment. PATIENTS AND METHODS: Retrospective review of children diagnosed with intussusception from January 2009 to December 2013, identifying early recurrences as those that occurred between 12-72 hours after successful enema reduction and comparing the results with current literature. RESULTS: A total of 121 children (77 male - 44 female), with a mean age of 18,9±2,7 months and weight of 10,77±0,57 kg (CI 95%) were treated for intussusception. Enema reduction was attempted in 90,7% (n= 88) of the cases, with a success rate of 76,1% (n= 67). Early recurrence rate was 6% (n= 4), without associated complications, which is similar to recent meta-analysis results (5,4%); however, three patients required surgical exploration. Mean length of stay was 2 days for enema-reduced intussusception, which resulted in a total cost of 2,076.67 euro per patient. CONCLUSION: The low recurrence rate and scarce risk of complications suggests that an 8 to 12 hour observation is a feasible alternative to hospital admission, which results in social advantages including family welfare as well as management costs. These results are a starting point for prospective randomized controlled trials comparing both treatment modalities.

INTRODUCCION/OBJETIVO: En la literatura actual existe debate en cuanto a la necesidad de ingresar a los pacientes con invaginación intestinal (II) después de la reducción exitosa mediante enema. El propósito de este estudio es caracterizar la recidiva de las II en nuestro medio para valorar la posibilidad del tratamiento ambulatorio. PACIENTES Y METODOS: Estudio retrospectivo de los niños atendidos por II entre 2009 y 2013 definiendo como recidiva temprana la que ocurre entre las 12-72 horas post-reducción, comparando los resultados con la literatura actual. RESULTADOS: Se trataron 121 niños (77 varones - 44 mujeres), con edad de 18,9±2,7 meses y peso de 10,77±0,57 kg (IC 95%), por II. Se intentó reducción mediante enema en 90,7% (n= 88) de los casos, siendo efectivo en un 76,1% (n= 67). La tasa de recidiva temprana fue del 6% (n= 4), sin complicaciones asociadas, similar a lo referido en estudios de meta-análisis recientes (5,4%); tres precisaron tratamiento quirúrgico. La estancia hospitalaria media es de 2 días para las II tratadas conservadoramente, lo que supuso un gasto promedio de 2.076,67 euros por ingreso. CONCLUSION: Dada la baja tasa de recidiva temprana y escaso riesgo de complicaciones, la observación durante 8-12 horas es una alternativa al ingreso hospitalario, lo que conllevaría ventajas de bienestar socio-familiar y de gestión. Estos resultados sirven como punto de partida para estudios prospectivos randomizados entre ambas modalidades de tratamiento.

Significant lethality following liver resection in A20 heterozygous knockout mice uncovers a key role for A20 in liver regeneration.

Hepatic expression of A20, including in hepatocytes, increases in response to injury, inflammation and resection. This increase likely serves a hepatoprotective purpose. The characteristic unfettered liver inflammation and necrosis in A20 knockout mice established physiologic upregulation of A20 as integral to the anti-inflammatory and anti-apoptotic armamentarium of hepatocytes. However, the implication of physiologic upregulation of A20 in modulating hepatocytes' proliferative responses following liver resection remains controversial. To resolve the impact of A20 on hepatocyte proliferation and the liver's regenerative capacity, we examined whether decreased A20 expression, as in A20 heterozygous knockout mice, affects outcome following two-third partial hepatectomy. A20 heterozygous mice do not demonstrate a striking liver phenotype, indicating that their A20 expression levels are still sufficient to contain inflammation and cell death at baseline. However, usually benign partial hepatectomy provoked a staggering lethality (>40%) in these mice, uncovering an unsuspected phenotype. Heightened lethality in A20 heterozygous mice following partial hepatectomy resulted from impaired hepatocyte proliferation due to heightened levels of cyclin-dependent kinase inhibitor, p21, and deficient upregulation of cyclins D1, E and A, in the context of worsened liver steatosis. A20 heterozygous knockout minimally affected baseline liver transcriptome, mostly circadian rhythm genes. Nevertheless, this caused differential expression of >1000 genes post hepatectomy, hindering lipid metabolism, bile acid biosynthesis, insulin signaling and cell cycle, all critical cellular processes for liver regeneration. These results demonstrate that mere reduction of A20 levels causes worse outcome post hepatectomy than full knockout of bona fide liver pro-regenerative players such as IL-6, clearly ascertaining A20's primordial role in enabling liver regeneration. Clinical implications of these data are of utmost importance as they caution safety of extensive hepatectomy for donation or tumor in carriers of A20/TNFAIP3 single nucleotide polymorphisms alleles that decrease A20 expression or function, and prompt the development of A20-based liver pro-regenerative therapies.

1236 C/T and 3435 C/T polymorphisms of the ABCB1 gene in Mexican breast cancer patients.

MDR1, which is encoded by the ABCB1 gene, is involved in multidrug resistance (hydrophobic), as well as the elimination of xenotoxic agents. The association between ABCB1 gene polymorphisms and breast cancer risk in different populations has been described previously; however, the results have been inconclusive. In this study, we examined the association between polymorphisms 3435 C/T and 1236 C/T in the ABCB1 gene and breast cancer development in Mexican women according to their menopausal status and molecular classification. Molecular subtypes as well as allele and genotype frequencies were analyzed. A total of 248 women with initial breast cancer diagnosis and 180 ethnically matched, healthy, unrelated individuals were enrolled. Polymerase chain reaction-restriction fragment length polymorphism was performed to detect polymorphisms 3435 C/T and 1236 C/T in the ABCB1 gene. Premenopausal T allele carriers of the 3435 C/T polymorphism showed a 2-fold increased risk of breast cancer with respect to the reference and postmenopausal groups, as well as triple-negative expression regarding the luminal A/B molecular subrogated subtypes. In contrast, the CT genotype of the 1236 polymorphism was a protective factor against breast cancer. We conclude that the T allele carrier of the 3435 C/T polymorphism in the ABCB1 gene in combination with an estrogen receptor-negative status may be an important risk factor for breast cancer development in premenopausal women.

Association between polymorphisms in the thymidylate synthase gene and risk of breast cancer in a Mexican population.

Breast cancer (BC) is the leading cause of cancer-related deaths among women in Mexico. Two single-nucleotide polymorphisms (SNPs) in the thymidylate synthase (TS) gene, the 28-base pair (bp) tandem repeat in the TS 5'-untranslated enhanced region (TSER) and the 6-bp insertion/deletion in the TS 3'-untranslated region (TS 3'-UTR), increase the rate of misincorporation of uridylate into DNA and may lead to chromosomal damage. We examined the association between these polymorphisms and BC risk in Mexican women according to menopause status. Mexican patients with initial BC diagnosis (N = 230) and 145 individuals from a reference general population group (RGP) were included. For statistical analysis, the BC group was divided into pre- and post-menopause groups (PRE and POST groups, respectively). We analyzed both TS polymorphisms (TSER and TS 3'-UTR) using polymerase chain reaction. Finetti analysis was used to evaluate inter-and intra-group differences. The results showed a high frequency for the 3R and ins6 alleles in the BC, RGP, PRE, and POST groups. No significant differences were observed for the TS and TSER genotype and allele frequency distributions between groups. We found that the TSER and TS 3'-UTR SNPs are not associated with BC risk in Mexican patients.

Characterization of bone cements prepared with functionalized methacrylates and hydroxyapatite.

Bone cements prepared with methyl methacrylate and either methacrylic acid or diethyl amino ethyl methacrylate as comonomers were characterized by infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, dynamic mechanical thermal analysis, and mechanical testing. Selected formulations containing these functionalized methacrylates were filled with hydroxyapatite and studied in terms of their properties in tension, compression and bending, and X-ray diffraction. It was found that residual monomer was not greatly affected by the presence of either acid or basic comonomers in the unfilled bone cements. In contrast, molecular weight, curing times, and glass transition temperature were composition dependent. For samples with acidic comonomer, a faster curing time, higher molecular weight, and higher glass transition temperatures were observed with respect to those with the basic comonomer. X-ray diffraction revealed that the crystalline structure was not affected by the nature of comonomer in the bone cement while scanning electron microscopy showed that hydroxyapatite remained as clusters in the bone cement. The mechanical properties of filled bone cements depended mainly on composition and type of testing. Hydroxyapatite-filled bone cements fullfilled the minimum compressive strength (70 MPa) required for bone cement use. However, the minimum tensile strength (30 MPa) was only fullfilled by cements prepared without comonomer and those containing methacrylic acid. The minimum bending strength requirement (50 MPa) was not satisfied by any of the formulations studied.

Intrinsic motivation among regular, special, and alternative education high school students.

This study examined motivationally related variables among three types of high school students. In particular, students' perceptions of competence, control, parental autonomy support, teacher autonomy support, peer autonomy support, and academic coping were investigated. Two hundred fifty-one juniors and seniors (104 regular education, 93 alternative education, and 54 special education) from a large Southern California school district participated. Significant group differences were found on measures of perceived competence, academic coping, and parental autonomy support. Specifically, regular education students had a higher level of self-reported academic competence than did special education students. Further, regular education and special education students reported that their parents were more involved in their lives as compared with alternative education students. Finally, regular education students reported a higher level of academic anxiety than did special education and alternative education students; however, regular education students had the highest level of positive coping. The implications of these findings are discussed.

[Technic for recovery of instruments fractured in the root canal, using cyanoacrylate cement (in vitro)]. / Técnica de recuperación de instrumentos fracturados dentro del conducto radicular, por medio del uso de cemento de cianoacrilato (in vitro).

A technique for retrieving and extracting mental fragments from root canals is presented, in which adhesives of cyanoacrylate esters are applied by dripping through hypodermic needles with their bevel edges previously trimmed in two sharp, angled slopes to facilitate cutting through the dentine around the metal fragment imbedded in the root canal, and prepared with high and low-speed funneled burrs. Besides being simple to handle, this technique has the advantage of employing equipment which is easy to acquire and construct.