Cervical length measurement between 11 and 13 + 6 weeks of pregnancy: Comparison of maternal and ultrasonographic characteristics between term and preterm deliveries.

OBJECTIVE: The aim of this study was to evaluate the maternal and ultrasonographic characteristics of pregnant women who underwent cervical length (CL) measurement by transvaginal ultrasound between 11 and 13 + 6 weeks of gestation and who delivered at term or preterm. METHODS: A retrospective cohort study was carried out between March 2013 and December 2018 by analyzing ultrasound data of singleton pregnant women who underwent CL measurement by transvaginal ultrasound during the first trimester scan. CL was compared between the two groups (full-term and preterm birth [PB]) using Student's t-test. RESULTS: A total of 5097 pregnant women were enrolled, of whom 5061 (99.3%) had term and 36 (0.7%) had PB < 34 weeks. CL measurements did not differ between the term and preterm groups (36.62 vs. 37.83 mm, p = 0.08). Maternal age showed a significant and linear association with CL (r = 0.034, p = 0.012) and CRL (r = 0.086, p < 0.001). Smoking status was associated with shorter CL (36.64 vs. 35.09 mm, p = 0.003). When we analyzed the CL of the pregnant women in the term and preterm groups, according to the gestational age cut-offs for prematurity (28, 30, 32, and 34 weeks), we found that there was no significant difference between the measurements in all groups (p > 0.05). CONCLUSION: We observed no significant differences between CL measurements between 11 and 13 + 6 weeks in pregnant women who had preterm and term deliveries. Gestational age and CRL showed a significant and linear association with CL measurement.

The Hip of Children with Congenital Zika Syndrome: A Prospective Observational Study.

OBJECTIVE: To assess the clinical and radiographic characteristics of hip joint deformities in children with congenital Zika syndrome (CZS), and the evolution of hip joint deformities in affected infants for the first 3 years of life. STUDY DESIGN: This prospective observational study evaluated orthopedic clinical examinations performed every 3 months to assess hip flexion and extension, lateral and medial rotation, and abduction and adduction, as well as lower limb muscle length and tone. The biannual radiograph comprised anteroposterior panoramic pelvic radiographs with the lower limbs in extension. Percentage of migration was used as a radiographic study tool to measure and evaluate linear hip displacement. RESULTS: From November 2018 to March 2020, we followed 30 children with CZS, of whom 15 (50%) had normal pelvic radiographs on admission; 5 (33.3%) developed hip displacement by the second radiograph examination. During follow-up radiographic examinations, 20 of the 30 children (66.7%) were diagnosed with hip displacement and/or dislocation of at least 1 side, and 10 of the 30 (33.3%) remained normal. Among 30 affected patients, 13 (43.3%) had hip displacement on the right side and 9 (30%) on the left side. Logistic regression analysis revealed that spasticity (P = .0033; OR, 15.9) and ophthalmologic abnormalities (P = .0163; OR, 16.9) were associated with hip dislocation during follow-up. CONCLUSIONS: Pelvic radiographic follow-up for all children with CZS will complement physical examination, diagnosis, and monitoring for hip joint deformities.

Incidence of bradycardia during noradrenaline or phenylephrine bolus treatment of postspinal hypotension in cesarean delivery: A randomized double-blinded controlled trial.

The treatment of choice for spinal anesthesia-induced hypotension during cesarean section is phenylephrine. As this vasopressor can cause reflex bradycardia, noradrenaline is a suggested alternative. This randomized double-blinded controlled trial included 76 parturients undergoing elective cesarean delivery under spinal anesthesia. Women received noradrenaline in bolus doses of 5 mcg or phenylephrine in bolus doses of 100 mcg. These drugs were used intermittently and therapeutically to maintain systolic blood pressure ≥ 90% of its baseline value. The primary study outcome was bradycardia incidence (<60 bpm) with intermittent bolus administration of these drugs. Secondary outcomes included extreme bradycardia (<40 bpm), number of bradycardia episodes, hypertension (systolic blood pressure > 120% of baseline value), and hypotension (systolic blood pressure < 90% of baseline value and requiring vasopressor use). Neonatal outcomes per the Apgar scale and umbilical cord blood gas analysis were also compared. The incidence of bradycardia in both groups (51.4% and 70.3%, respectively; p = 0.16) were not significantly different. No neonates had umbilical vein or artery pH values below 7.20. The noradrenaline group required more boluses than phenylephrine group (8 vs. 5; p = 0.01). There was no significant intergroup difference in any of the other secondary outcomes. When administered in intermittent bolus doses for the treatment of postspinal hypotension in elective cesarean delivery, noradrenaline, and phenylephrine have a similar incidence of bradycardia. When treating hypotension related to spinal anesthesia in obstetric cases, strong vasopressors are commonly administered, thought these can also have side effects. This trial assessed bradycardia after bolus administration of noradrenaline or phenylephrine, and found no difference in risk for clinically meaningful bradycardia.

Evaluation and monitoring of eye findings in children exposed to Zika virus during gestation: 3 years of follow-up.

INTRODUCTION: Congenital Zika syndrome (CZS) is a recently described disease. Our main objective was to evaluate and monitor, over 3 years, the ophthalmoscopic findings in children exposed to zika virus (ZIKV) during gestation. METHODS: This prospective observational study was conducted in Rio de Janeiro, Brazil, between April 2016 and May 2019. We evaluated two groups with exanthema serving as a proxy for viremia: (i) children whose mothers had exanthema during pregnancy and (ii) children who had microcephaly without maternal exanthema during pregnancy. We performed indirect ophthalmoscopy at recruitment and every 6 months thereafter. We also tested the association between ocular findings with maternal exanthema, microcephaly, CZS and maternal infection confirmed by reverse transcriptase quantitative polymerase chain reaction and gender. RESULTS: Of the 72 children included, 16 (22.2%) had optic nerve and/or retinal lesions. All 16 had CZS and 15 (93.7%) had microcephaly (14 at birth and 1 postnatally). The child with postnatally acquired microcephaly was born to a mother without exanthema during pregnancy. Fifty-six (77.8%) of the 72 children were followed for a median time of 24 months and none exhibited differences between admission and follow-up examinations. After logistic regression, only microcephaly at birth was associated with eye abnormalities (odds ratio, 77.015; 95% confidence interval, 8.85-670.38; p < 0.001). CONCLUSION: We observed that there was no progression of the lesions over the follow-up period. We also showed that the eye findings were associated only with microcephaly at birth. Attention should be paid to all children born during a ZIKV epidemic, regardless of maternal exanthema and/or microcephaly at birth.

Predictors for single-agent resistance in FIGO score 5 or 6 gestational trophoblastic neoplasia: a multicentre, retrospective, cohort study.

BACKGROUND: Patients with gestational trophoblastic neoplasia who have an International Federation of Gynaecology and Obstetrics (FIGO) risk score of 5 or 6 usually receive non-toxic single-agent chemotherapy as a first-line treatment. Previous studies suggest that only a third of patients have complete remission, with the remaining patients requiring toxic multiagent chemotherapy to attain remission. As stratification factors are unknown, some centres offer multiagent therapy upfront, resulting in overtreatment of many patients. We aimed to identify predictive factors for resistance to single-agent therapy to inform clinicians on which patients presenting with a FIGO score of 5 or 6 are likely to benefit from upfront multiagent chemotherapy. METHODS: We did a multicentre, retrospective, cohort study of patients with gestational trophoblastic neoplasia presenting with a FIGO score of 5 or 6, who received treatment at three gestational trophoblastic neoplasia reference centres in the UK, Brazil, and the USA between Jan 1, 1964, and Dec 31, 2018. All patients who had been followed up for at least 12 months after remission were included. Patients were excluded if they had received a non-standard single-agent treatment (eg, etoposide); had been given a previously established first-line multiagent chemotherapy regimen; or had incomplete data for our analyses. Patient data were retrieved from medical records. The primary outcome was the incidence of chemoresistance after first-line or second-line single-agent chemotherapy. Variables associated with chemoresistance to single-agent therapies were identified by logistic regression analysis. In patient subgroups defined by choriocarcinoma histology and metastatic disease status, we did bootstrap modelling to define thresholds of pretreatment human chorionic gonadotropin concentrations and identify groups of patients with a greater than 80% risk (ie, a positive predictive value [PPV] of 0·8) of resistance to single-agent chemotherapy. FINDINGS: Of 5025 patients with low-risk gestational trophoblastic neoplasia, we identified 431 patients with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6. All patients were followed up for a minimum of 2 years. 141 (40%) of 351 patients developed resistance to single-agent treatments and required multiagent chemotherapy to achieve remission. Univariable and multivariable logistic regression revealed metastatic disease status (multivariable logistic regression analysis, odds ratio [OR] 1·9 [95% CI 1·1-3·2], p=0·018), choriocarcinoma histology (3·7 [1·9-7·4], p=0·0002), and pretreatment human chorionic gonadotropin concentration (2·8 [1·9-4·1], p<0·0001) as significant predictors of resistance to single-agent therapies. In patients with no metastatic disease and without choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 411 000 IU/L or higher yielded a PPV of 0·8, whereas in patients with either metastases or choriocarcinoma, a pretreatment human chorionic gonadotropin concentration of 149 000 IU/L or higher yielded the same PPV for resistance to single-agent therapy. INTERPRETATION: Approximately 60% of women with gestational trophoblastic neoplasia presenting with a FIGO risk score of 5 or 6 achieve remission with single-agent therapy; almost all remaining patients have complete remission with subsequent multiagent chemotherapy. Primary multiagent chemotherapy should only be given to patients with metastatic disease and choriocarcinoma, regardless of pretreatment human chorionic gonadotropin concentration, or to those defined by our new predictors. FUNDING: None. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.

Folinic acid rescue during methotrexate treatment for low-risk gestational trophoblastic neoplasia - How much is just right?

OBJECTIVE: To compare the outcomes of patients with low-risk gestational trophoblastic neoplasia (GTN) treated with 8-day methotrexate (MTX) with two different regimens of folinic acid (FA). METHODS: Retrospective cohort study of low-risk GTN followed at Rio de Janeiro Federal University, from January/2000-December/2019 with 8-day MTX with FA at 0.1 mg/kg versus 15 mg fixed dose. RESULTS: Among 667 patients with low-risk GTN, 323 were treated with FA at 0.1 mg/kg and 142 with FA at 15 mg fixed dose. The weight-based and fixed dose groups were comparable in terms of clinical profile but did differ in the hCG pretreatment level (8883 versus 5127 IU/L, p < 0.01) and FIGO risk score 5/6 (3.4% versus 18.3%, p < 0.01), respectively. Despite this, there was no difference in the remission rate in first-line treatment (76.8 versus 81%, p = 0.33), although FA at 0.1 mg/kg had a significantly higher number of chemotherapy cycles to remission (5 versus 4, p < 0.01), need to delay chemotherapy due to toxicity (6.8 versus 2.8%, p < 0.01) and time to remission, (12 versus 8 weeks, p < 0.01), respectively. A logistic regression analysis showed that the different FA rescue regimens appeared comparable in terms of achieving remission in first-line chemotherapy for low-risk GTN (OR:5.16, CI95%:0.84-31.64, p = 0.08). CONCLUSION: FA with 15 mg fixed dose as compared to 0.1 mg/kg of FA was associated with similar primary remission rate, relapse or death among low-risk GTN treated with 8-day MTX. This regimen is highly practical, reduces visits to health facilities, appears equally safe and may be preferable with the 8-day MTX regimen in the treatment of low-risk GTN.

Premature rupture of membranes - A cause of foetal complications among lupus: A cohort study, systematic review and meta-analysis.

OBJECTIVE: The present study aimed to analyse the frequency of premature rupture of membranes (PROMs) among 190 women with systemic lupus erythematosus (SLE) followed up at the Hospital Universitário Pedro Ernesto from 2011 to 2018 and to review the literature on PROM in patients with SLE. METHODS: A cohort study of SLE patients was conducted by analysing the following variables: sociodemographic characteristics, clinical manifestations of lupus, modified disease activity index for pregnancy, drugs used during pregnancy, intercurrent maternal infections and obstetric outcomes. Additionally, seven electronic databases (PubMed, Embase, Cochrane, Scielo, Scielo Brazil, Virtual Health Library Regional Portal and Google Scholar) were systematically searched. The search was updated on 3 February 2020. RESULTS: Infections (relative risk (RR): 3.26, 95% confidence interval (CI): 1.5-6.7, p = .001), history of serositis (RR: 2.59, 95% CI: 1.31-5.11, p = .006) and anti-RNP positivity (RR: 3.08, 95% CI: 1.39-6.78, p = .005) were associated risk factors for PROM, while anti-RNP positivity (RR: 3.37, 95% CI: 1.35-8.40; p = .009) were associated with premature PROM (PPROM). The prevalence of PROM and PPROM was 28.7% and 12.9%, respectively. In the systematic review, the prevalence of PROM and PPROM was 2.7%-35% (I2 = 87.62%) and 2.8%-20% (I2 = 79.56%), respectively. CONCLUSIONS: PROM, both at term and preterm, occurs more frequently in women with lupus than in the general population. A history of serositis, anti-RN, infections and immunosuppression during pregnancy may increase the susceptibility to PROM. The systematic review did not find any study with the main objective of evaluating PROM/PPROM in women with lupus.

Gestational trophoblastic neoplasia lethality among Brazilian women: A retrospective national cohort study.

OBJECTIVE: To investigate GTN lethality among Brazilian women comparing cases of death by GTN with those who survived, thereby identifying factors associated with GTN lethality. METHODS: We retrospectively reviewed medical records of women with GTN treated at ten Brazilian GTN Reference Centers, from January 1960 to December 2017. We evaluated factors associated with death from GTN and used Cox proportional hazards regression models to identify independent variables with significant influence on the risk of death. RESULTS: From 2186 patients with GTN included in this study, 2092 (95.7%) survived and 89 (4%) died due to GTN. When analyzing the relative risk (RR), adjusted for WHO/FIGO score, patients with low risk disease had a significantly higher risk of death if they had choriocarcinoma (RR: 12.40), metastatic disease (RR: 12.57), chemoresistance (RR: 3.18) or initial treatment outside the Reference Center (RR: 12.22). In relation to patients with high-risk GTN, these factors were significantly associated with death due to GTN: the time between the end of antecedent pregnancy and the initiation of chemotherapy (RR: 4.10), metastatic disease (RR: 14.66), especially in brain (RR: 8.73) and liver (RR: 5.76); absence of chemotherapy or initial treatment with single agent chemotherapy (RR: 10.58 and RR: 1.81, respectively), chemoresistance (RR: 3.20) and the initial treatment outside the Reference Center (RR: 28.30). CONCLUSION: The risk of mortality from low and high-risk GTN can be reduced by referral of these patients to a Reference Center or, if not possible, to involve clinicians in a Reference Center with consultation regarding management.

Fat Mass Ratio in Brazilian HIV-infected Patients Under Antiretroviral Therapy and Its Relationship With Anthropometric Measurents.

INTRODUCTION: Human immunodeficiency virus-related lipodystrophy is characterized by a variety of phenotypes and metabolic changes; however, consensus has not yet been reached on its diagnostic criteria. Different cutoff values for fat mass ratio have been proposed for this specific population as an objective diagnostic criterion for lipodystrophy. This study aimed to establish sex-specific reference values for fat mass ratio and to correlate them with anthropometric measurements for the diagnosis of human immunodeficiency virus-related lipodystrophy. METHODOLOGY: A cross-sectional study was performed on 189 human immunodeficiency virus-infected patients under antiretroviral therapy. Anthropometric measurements were evaluated, and body composition was determined using dual-energy X-ray absorptiometry. Fat mass ratio was calculated as the ratio of the percentage of the trunk fat mass and the percentage of the lower limb fat mass. RESULTS: One hundred and thirty-two patients (69%) presented lipodystrophy by objective criteria. In men, the cutoff for the fat mass ratio was 1.55 (area under the receiver operating characteristic curve: 0.73 [95% confidence interval: 0.62-0.83], p = 0.000008), with a sensitivity of 62.5%, a specificity of 70.5%, a positive predictive value of 77.8%, and a negative predictive value of 53.4%. In women, the cutoff for the fat mass ratio was 0.959 (area under the receiver operating characteristic curve: 0.70 [95% confidence interval: 0.56-0.85], p = 0.03), with a sensitivity of 83.60%, a specificity of 61.5%, a positive predictive value of 90.2%, and a negative predictive value of 47.1%. Fat mass ratio was positively correlated with waist circumference (men: r = 0.246, p = 0.019; women: r = 0.302, p = 0.014) and neck circumference (men: r = 0.304, p = 0.004; women: r = 0.366, p = 0.003) in both sexes; and body mass index (r = 0.288, p = 0.006) and waist-hip ratio (r = 0.288, p = 0.006) in men. CONCLUSION: The fat mass ratio evaluated using dual-energy X-ray absorptiometry with the sex-specific cutoffs is an objective tool to define human immunodeficiency virus-related lipodystrophy.

Influence of non-pharmacological obstetric interventions on adverse outcomes of childbirth under regional analgesia.

Background We examined the influence of companionship and the use of complementary therapies on adverse outcomes in parturients under regional analgesia. Methods This study is a single-center retrospective cohort of 986 term pregnant women, and it was based on data from medical records (hospitalization period: November 2012-November 2018). The women were in the active phase of labor under regional analgesia. A statistical program was used to search for an association between companionship and the use of complementary therapies with sample data. Bi- and multivariate logistic regressions based on significant associations were used to analyze the potential intervening variables in the adverse outcomes. Results Models were constructed for each of the maternal adverse outcomes. Childbirth complications were significantly associated with complementary therapies [adjusted odds ratio (AOR) = 0.42; 95% confidence interval (CI) = 0.28-0.63; P < 0.001] and companionship (AOR = 0.36; 95% CI = 0.22-0.57; P < 0.001). Prolonged maternal hospitalization was significantly associated with companionship (AOR = 0.57; 95% CI = 0.36-0.92; P < 0.05). Unplanned cesarean section showed a significant association with complementary therapies (AOR = 0.05; 95% CI = 0.01-0.47; P < 0.01). Conclusion The likelihood of childbirth complications and prolonged maternal hospitalization is reduced by companionship, whereas the likelihood of childbirth complications and cesarean section rates is reduced by the use of complementary therapies.

Assessment of Fetal Lung Maturity Using Quantitative Ultrasound Analysis in Patients with Prelabor Rupture of Membranes.

INTRODUCTION: Prelabor rupture of membranes (PROM) is a frequent clinical situation, and the decision about the best time for delivery remains controversial, mainly due to the risk of neonatal respiratory morbidity (NRM). Assessment of fetal lung maturity using ultrasound, a safe method and widely used in current obstetrical practice, could change this scenario. This study was designed to evaluate the ability of quantitative ultrasound method QuantusFLM® to predict NRM in patients with PROM and whether maternal BMI, gestational age, occurrence of the disease, and presence of oligohydramnios influenced the performance. METHODS: Patients with singleton gestations, diagnosis of PROM, and gestational age between 24 and 38 weeks and 6 days were included. Fetal lung image was acquired by ultrasound within 48 h prior to delivery and analyzed by QuantusFLM®. The results were then paired with neonatal outcomes to assess the program's ability to predict the NRM in this specific group. A logistic regression model was created to analyze factors that could affect the test results. RESULTS: Fifty-four patients were included. Mean maternal BMI was 28.99 kg/m2, and in 25 patients (46.2%), oligohydramnios was observed at the time of examination. Mean gestational age at delivery was 35 weeks and 4 days, and the NRM prevalence was of 18.5%. QuantusFLM® predicted NRM with a 60% sensitivity, 79.5% specificity, 40% positive predictive value, 89.7% negative predictive value, and 75.6% accuracy. Maternal BMI, disease occurrence, presence of oligohydramnios, and gestational age did not interfere with the evaluation. CONCLUSION: This study demonstrates a good accuracy of QuantusFLM® as a NRM predictor in patients with PROM, with particular reliability in identifying that pulmonary maturity has already occurred.

Doubly resonant sum frequency spectroscopy of mixed photochromic isomers on surfaces reveals conformation-specific vibronic effects.

Doubly resonant infrared-visible sum-frequency generation (DR-IVSFG) spectroscopy, encompassing coupled vibrational and electronic transitions, provides a powerful method to gain a deep understanding of nuclear motion in photoresponsive surface adsorbates and interfaces. Here, we use DR-IVSFG to elucidate the role of vibronic coupling in a surface-confined donor-acceptor substituted azobenzene. Our study reveals some unique features of DR-IVSFG that have not been previously reported. In particular, vibronic coupling resulted in prominent SFG signal enhancement of selective stretching modes that reveal electronic properties of coexisting photochromic isomers. Our analysis explores two concepts: (1) In partially isomerized azobenzene at the surface, coupling of the fundamental vibrations to the S0 → S1 transition is more prominent for the cis isomer due to symmetry breaking, whereas coupling to the S0 → S2 transition was dominant in the trans isomer. (2) A strong coupling between the fundamental vibrations and the valence π-electron density, promoted by the initial absorption of an infrared photon, may result in suppression of the intensity of the hot band vibronic transition. This may translate into a suppressed sum-frequency generation signal at sum frequency wavelengths resonant with the S0 → S2 transition of the trans isomer. The weaker coupling of the fundamental vibrations to the non-bonding electron density localized on the azo group can therefore produce detectable sum-frequency generation at the resonance wavelength of the weaker S0 → S1 transition in the cis form. These results are explained in the framework of a linear coupling model, involving both Franck-Condon and Herzberg-Teller coupling terms. Our theoretical analysis reveals the important role played by molecular conformation, orientation, and vibronic interference in DR-SFG spectroscopy.

Can the indicators of chronic ethanol consumption be minimized by a continuous flaxseed intake?

The aim of this study was to evaluate the use of flaxseed in animals subjected to ethanol-induced hepatotoxicity. Twenty-four male rats were divided into four groups (n = 6): control group (CG) which received a control diet and water ad libitum; flaxseed group (FG) which received control diet with an addition of 25% flaxseed flour and water ad libitum; ethanol control group (ECG) which received control diet and a solution of 10% ethanol (v/v) as the only liquid source; and ethanol flaxseed group (EFG) which received control diet with an addition of 25% flaxseed flour and a solution of 10% ethanol (v/v) as the only liquid source. The animals were euthanized at 60 days, when blood was collected for biochemical analysis and liver was collected for histomorphometric analysis. Rats fed with diets containing flaxseed showed lower values of alkaline phosphatase (P = 0.020) and lower concentration of total bilirubin (P = 0.006), direct bilirubin (P = 0.013) and indirect bilirubin (P = 0.018) compared to ECG and EFG. The groups receiving flaxseed diets demonstrated higher expression of superoxide dismutase (SOD) enzyme (P < 0.001) than CG and ECG but did not affect thiobarbituric acid (TBARS) expression (P = 0.055). Regarding liver analysis, the ECG and EFG showed larger hepatocyte nuclei and paler cytoplasm than the groups who had not received ethanol, and less in fluid accumulation (oedema) in the cytoplasm than was seen in the FG and EFG livers. These latter two groups showed fewer fatty cells than was seen in the groups that had not been given flaxseed, so that the diagnosis of hepatic steatosis was not justified. In conclusion, therefore, this study showed that the indicators of ethanol chronic consumption can be reduced by the introduction of continuous flaxseed dietary intake.

Tuning the Surface Ordering of Self-Assembled Ionic Surfactants on Semiconducting Single-Walled Carbon Nanotubes: Concentration, Tube Diameter, and Counterions.

We report direct spectroscopic measurements of the macromolecular organization of ionic surfactants on the surface of semiconducting single-walled carbon nanotubes (SWCNTs) within solution-processed thin films. By using vibrational sum frequency generation (VSFG) spectroscopy, sensitive measurements of interfacial surfactant ordering were obtained as a function of surfactant concentration for sodium dodecyl sulfate (SDS)-encapsulated (6,5) and (7,6) SWCNTs with and without excess electrolytes. Anionic surfactants are known to effectively stabilize SWCNTs. The current models suggest a strong influence of the dispersion conditions on the surfactant interfacial macromolecular organization and self-assembly. Direct experimental probes of such an organization using nanotubes of specific chirality are needed to validate the existing models. We found that as the bulk SDS concentration increases near the surfactant critical micelle concentration, the interfacial ordering increased, approaching the formation of cylindrical-like micelles with the nanotube at the core. At the higher surfactant concentrations measured here, the (6,5) SWCNTs produced more ordered structures relative to those with the (7,6) SWCNTs. The relatively larger-diameter (7,6) chiral tubes support enhanced van der Waals (vdW) interactions between the tube carbon surface and the surfactant methylene chain groups that likely increase the density of gauche defects. A new effect arises when the precursor solution is exposed to a small concentration of divalent Ca2+ counterions. We postulate that a salt-bridging configuration on such highly curved surfaces decreases the ordering of interfacial surfactant molecules, resulting in compact, disordered structures. However, this phenomenon was not observed with excess Na+ ions at the same ionic strength. Instead, a modest increase in surfactant ordering was observed with the excess monovalent electrolyte. These results provide new insights for thin film solution processing of vdW nanomaterials and demonstrate that VSFG is a sensitive probe of surfactant organization on nanostructures.

Relationship between the risk factors for human papillomavirus infection and lower genital tract precursor lesion and cancer development in female transplant recipients.

BACKGROUND: This study aimed to analyze the relationship between the several risk factors for human papillomavirus (HPV) infection and its persistence and to assess the prevalence of the lower genital tract precursor lesions, cancer, and HPV infection in female transplant recipients, besides the most prevalent HPV types. METHODS: The methodology adopted was a cross-sectional study with a random sample of 61 patients. RESULTS: The results indicated 10 cases (16.4%) of lesions, 54.5% of the overall prevalence of HPV infection, and HPV 16 was the most common high-risk HPV type, followed by HPV 51/53/70. A multiple logistic regression was done and hormone use presented a statistically significant association with high-risk HPV infection (P=.037). No statistically significant association was identified for the set of all factors with the lesions studied. CONCLUSIONS: The high prevalence of HPV infection and its precursor lesions confirmed the importance of differential screening and follow-up of transplanted patients. Condom use must be encouraged. The study result also confirmed the importance of knowledge of the viral type, in order to analyze the impact of HPV immunization, particularly against HPV types that are not 16/18. The reasonable rate of other genotypes, besides the vaccine types, should be considered to evaluate vaccination strategies.

Substrate influence on the interlayer electron-phonon couplings in fullerene films probed with doubly-resonant SFG spectroscopy.

We present doubly-resonant sum frequency generation (DR-SFG) spectra of fullerene thin films on metallic and dielectric substrates as a way to investigate the interplay between nuclear and electronic coupling at buried interfaces. Modal and substrate selectivity in the electronic enhancement of the C60 vibrational signatures is demonstrated for excitation wavelengths spanning the visible range. While the SFG response of the totally symmetric Ag(2) mode of fullerene is distinctly coupled to the optically allowed electronic transition corresponding to the HOMO-LUMO+1 of C60 (ca. 2.6 eV), the T1u(4) vibrational mode appears to be coupled to a symmetry-forbidden HOMO-LUMO transition at lower energies (ca. 2.0 eV). For dielectric substrates, the DR-SFG intensity of the T1u(4) mode shows lack of enhancement for upconversion wavelengths off-resonance with the optically-dark LUMO. However, the T1u(4) mode shows a unique coupling to an intermediate state (∼2.4 eV) only for the fullerene films on the gold substrate. We attribute this coupling to unique interactions at the buried C60/gold interface. These results demonstrate the occurrence of clear electron-phonon couplings at the C60/substrate interfaces and shed light on the impact of these couplings on the optical response of electronically excited fullerene. This coupling may influence charge and energy transport in organic electronic devices mediated by vibrational motions. We also demonstrate a potential use of this added selectivity in chemical imaging.

Quantitative sum-frequency generation vibrational spectroscopy of molecular surfaces and interfaces: lineshape, polarization, and orientation.

Sum-frequency generation vibrational spectroscopy (SFG-VS) can provide detailed information and understanding of the molecular composition, interactions, and orientational and conformational structure of surfaces and interfaces through quantitative measurement and analysis. In this review, we present the current status of and discuss important recent developments in the measurement of intrinsic SFG spectral lineshapes and formulations for polarization measurements and orientational analysis of SFG-VS spectra. The focus of this review is to present a coherent description of SFG-VS and discuss the main concepts and issues that can help advance this technique as a quantitative analytical research tool for revealing the chemistry and physics of complex molecular surfaces and interfaces.

Evaluation of the adequacy of reference charts for the accurate identification of fetuses with bone length below the 5th percentile.

AIM: To identify reference charts for femoral and humeral lengths enabling appropriate identification of fetuses <5th percentile in one population. METHODS: Two samples of fetuses aged 14-40 weeks were selected from our institution's ultrasonographic database. Regression analysis was used to construct reference charts of femoral and humeral lengths based on the local population (n=901). Femur and humerus length measurements from a second sample (n=1240) were transformed into Z-scores using local and previously published equations. Z-score distributions were used to assess the appropriateness of reference curves for our population. Fetuses aged 18-24 weeks with measurements <5th percentile were identified using each reference equation. RESULTS: For femoral length, one equation other than the local equation yielded Z-score values within the standard normal distribution (P=0.10), but the histogram was skewed to the right. All Z-score distributions for humeral length fell within the normal distribution (P>0.05), but one was skewed to the right. The numbers of fetuses with femoral and humeral lengths <5th percentile in second-trimester ultrasound examinations varied widely among reference equations used. CONCLUSION: Most reference charts assessed underestimated the number of fetuses with long bone lengths <5th percentile in second-trimester ultrasound examinations and were thus unfit for interpretations of biometric data from the study population.

[Simultaneous diagnosis of pseudomeningocele, tethered cord syndrome and cerebrospinal fluid fistula: Report of a case]. / Diagnóstico simultáneo de pseudomeningocele, síndrome de médula anclada y fístula de líquido cefalorraquídeo: a propósito de un caso.

The clinical case is presented on a patient with an extensive sacral dysraphism, a history of myelomeningocele surgical repair in her childhood, as well as tethered cord syndrome. The patient was also diagnosed with pseudomeningocele and a cerebrospinal fluid cutaneous fístula. A surgical approach was used, with encouraging results being obtained in the clinical outcome of the patient. A review of the literature was performed to support the surgical decision in this case.

Accurate line shapes from sub-1 cm(-1) resolution sum frequency generation vibrational spectroscopy of α-pinene at room temperature.

Despite the importance of terpenes in biology, the environment, and catalysis, their vibrational spectra remain unassigned. Here, we present subwavenumber high-resolution broad-band sum frequency generation (HR-BB-SFG) spectra of the common terpene (+)-α-pinene that reveal 10 peaks in the C-H stretching region at room temperature. The high spectral resolution resulted in spectra with more and better resolved spectral features than those of the Fourier transform infrared, femtosecond stimulated Raman spectra in the bulk condensed phase and those of the conventional BB-SFG and scanning SFG spectroscopy of the same molecule on a surface. Experiment and simulation show the spectral line shapes with HR-BB-SFG to be accurate. Homogeneous vibrational decoherence lifetimes of up to 1.7 ps are assigned to specific oscillators and compare favorably to lifetimes computed from density functional tight binding molecular dynamics calculations. Phase-resolved spectra provided their orientational information. We propose the new spectroscopy as an attractive alternative to time domain vibrational spectroscopy or heterodyne detection schemes for studying vibrational energy relaxation and vibrational coherences in molecules at molecular surfaces or interfaces.