Decoupling of ion-transport from polymer segmental relaxation and higher ionic-conductivity in poly(ethylene oxide)/succinonitrile composite-based electrolytes having low lithium salt doping.

Only limited enhancement in room-temperature ionic-conductivity for poly(ethylene oxide), PEO, based electrolytes is possible due to coupling between ionic-conductivity and segmental relaxation. In the present study, we have achieved ionic-conductivity of 1.07 × 10-3 and 6.20 × 10-4 S cm-1 at 313 and 298 K, respectively, by adding 45 wt% of succinonitrile (SN) in PEO having low LiTFSI loading (Li : EO = 1 : 20). This enhancement in the ionic-conductivity is attributed to faster ion transport (diffusion coefficient, D = 3.63 × 10-5 cm2 s-1) occurring through the ion-transport channels as confirmed by positron annihilation lifetime spectroscopy. The ionic-transport through these channels is observed to be highly decoupled from the segmental relaxations as confirmed using broadband dielectric spectroscopy through Ratner's approach. The observed decoupling of ionic-conductivity from PEO segmental relaxation in PEO-SN composite-based electrolytes would be useful to design rather inexpensive all solid-state polymer electrolytes for Li ion batteries.

On enhancing the Li-ion conductivity of quasi-solid-state electrolytes by suppressing the flexibility of zeolitic imidazolate framework-8 via a mixed ligand strategy.

Zeolitic imidazole frameworks (ZIFs) have emerged as potential conductive materials for Li ion-transport in polymer solid state electrolytes. However, developing ZIFs with high Li ionic conductivity is rather limited due to their flexible frameworks allowing dual ion conduction. Herein, we have used a mixed ligand strategy for fine-tuning the aperture and enhancing the rigidity of ZIF-8, which restricts the passage of large size anions. Poly(ethylene oxide)-based quasi-solid state electrolytes utilizing mixed ligand ZIF-7-8 frameworks as passive fillers show a continuous enhancement in Li ion-conductivity exclusively attributed to modifications in the flexibility and pore architecture of ZIF-8 as confirmed through broadband dielectric spectroscopy and positron annihilation spectroscopy. This study shows that polymer segmental relaxation and conductivity relaxation processes are decoupled in these electrolytes. Consequently, our proposed approach provides a new strategy for manufacturing a polymer-based electrolyte with enhanced ionic conductivity.

High ionic conductivity and ion conduction mechanism in ZIF-8 based quasi-solid-state electrolytes: a positron annihilation and broadband dielectric spectroscopy study.

The low ionic conductivity and electrode-electrolyte interface instability issues with solid polymer electrolytes jeopardize their electrochemical performances in lithium-ion batteries (LIBs). The use of quasi-solid-state electrolytes (QSSEs) with concentrated Li salt embedded inside the pore networks of metal organic frameworks (MOFs) can successfully address the aforementioned issues. Owing to the sieve effect of zeolitic imidazolate framework-8 (ZIF-8) towards selective cation permeability over anions through the interconnected pore network, a unique QSSE with LiTFSI salt concentrated in the ZIF-8 skeleton used as a filler in poly(ethylene oxide) has been synthesized. LiTFSI gets embedded inside the interconnected pore network of ZIF-8 that furnishes unhindered pathways for Li+ ion migration leading to a very high ionic conductivity of ∼6 × 10-4 S cm-1. The higher ionic conductivity is directly related to the Li+ ion conduction through the pore network of ZIF-8 which has been experimentally evident from complementary methods viz. Positron annihilation and broadband dielectric spectroscopy. The design route towards these types of QSSEs encompassing porous MOFs paves the way for realizing Li superionic conductors suitable for practical application in commercial LIBs with high safety and stability.

Free Volume Mediated Decoupling of Ionic Conduction from Segmental Relaxation Leading to Enhancement in Ionic Conductivity of Polymer Electrolytes at Low Temperatures.

Coupling between segmental relaxation and ionic conduction has limited the ionic conductivity of flexible polymers like poly(ethylene oxide), PEO, based electrolytes especially at low temperatures where segmental relaxation becomes extremely slow. In the present study, we show that ionic conduction becomes decoupled from segmental relaxation in PEO-based electrolytes simply by loading succinonitrile (SN). As a result of SN interactions induced rigid chain packing of PEO, the semicrystalline morphology of PEO is completely altered along with the enhancement in number density of free volumes having smaller size and narrower size distribution. These free volumes provide additional pathways for ionic diffusion independent of segmental relaxations of PEO leading to decoupling of ionic diffusion from the segmental relaxation process. The decoupling finally leads to nearly two orders higher ionic conductivity (∼10-11 Scm-1)at glass transition temperature (Tg ∼ 210 K), than what is expected in the case of complete coupling.

[Surgical resection with ophthalmoplastic reconstruction : Gold standard in periocular basal cell carcinoma]. / Chirurgische Resektion mit ophthalmoplastischer Rekonstruktion : Goldstandard beim periokulären Basalzellkarzinom.

The gold standard for the treatment of periocular basal cell carcinoma is surgical resection followed by ophthalmoplastic reconstruction. The highest priority in most cases is the complete histopathologically controlled tumor excision. The histopathological preparation can be carried out in two stages by rapid overnight embedding or intraoperatively by a rapid frozen section procedure. A variety of reconstruction methods enable a customized and in most cases also a cosmetically and functionally attractive defect coverage. Postoperatively, a regularly performed tumor aftercare is essential.

[New treatment options for iridociliary tumors]. / Neue therapeutische Möglichkeiten bei iridoziliären Tumoren.

BACKGROUND: Benign iridal tumors rarely necessitate a therapeutic intervention. In contrast, malignant tumors of the iris can threaten the patient's life and eyesight and require early treatment to prevent the development of metastases. OBJECTIVE: Presentation of current treatment options for iridal tumors with special emphasis on iridal melanoma. METHODS: This article gives an overview of the current literature based on a PubMed search as well as own clinical experience. RESULTS: Treatment options for iridal and ciliary body melanomas comprise radiotherapeutic and surgical (eyeball-sparing and non-sparing) approaches. The eyeball-sparing surgical procedure of choice is block excision. While local tumor control rates and metastasis rates of block excision and radiotherapy are comparable, there are distinct differences especially between the spectra of complications. New treatment procedures include immunomodulatory approaches and targeted therapies. Using checkpoint inhibitors, no convincing enhancement of overall survival could be demonstrated for metastatic iridal melanoma, as is the case for cutaneous melanoma. In contrast, tumor vaccination with the help of tumor RNA-laden patient-derived dendritic cells seems to be a promising option for a subgroup of high-risk patients. Targeted therapies aiming to suppress the MAPK and PI3K/Akt pathways could not achieve any improvement in patient survival. CONCLUSION: For the primary treatment of iridal melanoma a surgical, eyeball-sparing approach and also when appropriate, radiotherapy can be recommended. In the future, eligible high-risk patients could profit from a tumor vaccination. To date, there is no effective systemic treatment for metastatic iridal melanoma.

[Clinico-echographic diagnostics of iris tumors]. / Klinisch-echographische Diagnostik bei Iristumoren.

BACKGROUND: The differentiation of iridic space-occupying lesions represents a regularly reoccurring diagnostic challenge. OBJECTIVE: This article presents an overview of the epidemiological data and describes the diagnostic procedure for iris tumors. MATERIAL AND METHODS: The article provides a review of the literature from PubMed and own clinical results. RESULTS: Melanocytic lesions comprise the vast majority of all iris tumors and include nevi and melanomas. Slit lamp biomicroscopy with standardized photography reveals two-dimensional planar tumor growth over time, which is the only recognized clinical surrogate finding for a malignant event. Ultrasound biomicroscopy (UBM) is additionally obligatory because it is the only method which enables documentation of the extent of tumor penetration, ciliary body involvement and internal structure of iris tumors. CONCLUSION: Serial slit lamp and UBM examinations with reproducible pupillary diameters are indispensable for the differentiation of cystic, solid and tumor-simulating lesions and for the detection of malignant transformation in iris tumors.

[CyberKnife®: new treatment option for uveal melanoma]. / CyberKnife®: Eine neue Therapieoption bei uvealem Melanom.

BACKGROUND: CyberKnife® stereotactic radiosurgery is a new treatment option for uveal melanoma. OBJECTIVE: This review outlines the technique of robot-assisted CyberKnife® therapy, as well as the pros and cons in the treatment of uveal melanoma. METHODS: The study provides a PubMed literature review and own preliminary clinical experiences. RESULTS: CyberKnife® therapy for choroidal and ciliary body melanomas shows comparable results concerning local tumor control and overall survival matching those of conventional therapies. With only low complication rates, a high level of quality of life can be conserved by possible preservation of visual acuity as well as the ocular globe. CONCLUSION: Stereotactic radiosurgery using CyberKnife® seems to be an efficient and safe therapeutic option for malignant melanomas affecting the choroid and ciliary body. Comparative studies with conventional radiation strategies are now a high priority.

Birth outcomes of Asian-Indian-Americans.

OBJECTIVE: This study examines the maternal characteristics and birth outcomes of infants of U.S. resident Asian-Indian-American (AIA) mothers and compares those to infants of U.S. resident Whites and African-American (AA) mothers. METHODS: Single live births to U.S. resident mothers with race/ethnicity coded on birth certificate as AIA, non-Hispanic White, or non-Hispanic AA were drawn from NCHS 1995 to 2000 U.S. Linked Live Birth/Infant Death files. RESULTS: Compared to AAs or Whites, AIAs have the lowest percentage of births to teen or unmarried mothers and mothers with high parity for age or with low educational attainment. After taking these factors into account, AIA had the highest risk of LBW, small-for-gestational age and term SGA births but a risk of infant death only slightly higher than Whites and far less than AAs. CONCLUSIONS: The birth outcomes of AIAs do not follow the paradigm that more impoverished minority populations should have greater proportions of low birth weight and preterm births and accordingly greater infant mortality rates.

Balancing the health benefits and environmental risks of pharmaceuticals: Diclofenac as an example.

Pharmaceuticals are designed to improve human and animal health, but even the most beneficial pharmaceuticals might raise some questions concerning the consequences of exposure to non-target organisms. To illustrate this situation and using diclofenac as a case-study, we analyze global consumption and occurrence data to identify hot spots of consumption without occurrence data, review the scientific literature on the harmful environmental effects to determine whether the observed concentrations in freshwater are of environmental concern, summarize the current pharmaceutical and environmental policies to highlight policy gaps, and suggest a series of research and policy recommendations, which can be summarized as follows: we need to improve the current knowledge on occurrence in freshwaters to properly implement environmental policies (i), diclofenac might pose a risk to non-target organisms in freshwater (ii); the harmful effects that some pharmaceuticals may have on the environment are not always addressed by environmental policies (iii).

A United States national reference for fetal growth.

OBJECTIVE: To develop a current national fetal growth curve that can be used as a common reference point by researchers to facilitate investigations of the predictors and consequences of small and large for gestational age delivery. METHODS: Single live births to United States resident mothers in 1991 (n = 3,134,879) were used for the development of this curve, which was compared with four previously published fetal growth curves. Techniques were developed to address cases with implausible birth weight-gestational age combinations and to smooth fetal growth curves across gestational age categories. RESULTS: In general, the previously published fetal growth curves underestimated the 1991 United States reference curve. This underestimation is most apparent during the latter weeks of gestation, approximately 33-38 weeks. CONCLUSION: Our findings indicate that the prevalence of fetal growth restriction (FGR) will vary markedly, depending on the fetal growth curve used. Furthermore, many previously published fetal growth curves no longer provide an up-to-date reference for describing the distribution of birth weight by gestational age and for determining FGR that is consistent with the most recent live birth data for the entire United States.

Determinants of prenatal care use in Hawaii: implications for health promotion.

This study examines the association between maternal sociodemographic characteristics and the receipt of different levels of prenatal care use (no care, inadequate, intermediate, adequate) in order to determine different patterns in the relationships between maternal characteristics and these distinct categories of prenatal care use. Using the 1979-1992 Hawaii live birth vital record file, single live births to Hawaii resident mothers of white, Hawaiian/part-Hawaiian, Filipino, or Japanese ethnicity, who did not indicate on the birth certificate that either parent was active duty military, were selected. Over one quarter of this study population did not initiate prenatal care in the first trimester. Given the high level of insurance coverage found in Hawaii, this finding is disconcerting, particularly in relation to the U.S. Year 2000 Objective of 90% initiation in the first trimester. Overall, the factors that predicted receipt of any prenatal care predicted more adequate use of prenatal care as well. Noteworthy exceptions were maternal age and ethnicity. Identifying these exceptions is important for the development of a more detailed understanding of risk factors related to use of prenatal care to better target program responses aimed at improving prenatal care use. In addition, these data suggest that removing financial barriers to access to care does not guarantee universal use of disease prevention and health promotion services.

Health of infant is the main reason for breast-feeding in a WIC population in Hawaii.

OBJECTIVE: To determine factors influencing infant feeding method choices among women who received services from the Special Supplemental Food Program for Women, Infants, and Children (WIC) during pregnancy in Hawaii. DESIGN: A retrospective survey mailed to all resident mothers who had live births in Hawaii between January 1, 1989, and March 31, 1989, and who received WIC services during pregnancy. SETTING: The state of Hawaii. SUBJECTS: The subjects were 322 mothers who received WIC services during pregnancy for whom data were complete, taken from a sample of 2,013 women who had live births in the state of Hawaii (51% response rate) between January 1, 1989, and March 31, 1989, of whom 324 participated in WIC during pregnancy. MAIN OUTCOME MEASURES: Infant feeding method (exclusive breast, exclusive formula or mixed) at hospital discharge. STATISTICAL ANALYSES PERFORMED: The chi 2 analysis for differences among feeding method groups and multiple logistic regression to calculate odds ratios for independent effects of maternal characteristics and other influences on feeding method choice. RESULTS: Reasons for infant feeding choice, timing of the choice, maternal age, parity, and place of residence were the main factor influencing infant method choice. Health of the infant was the primary reason for choice of feeding method and was the strongest determinant of exclusive breast-feeding (odds ratio = 23.99; confidence interval = 9.75-59.02; P < .0001) and was negatively related to the choice to formula-feed (odds ratio = 0.03; confidence interval = 0.01-0.08; P < .0001). APPLICATIONS: Relationship between WIC and hospital lactation consultants could enhance follow up in the hospital and after returning home with WIC mothers who prenatally state an intention to breast-feed. Convenience and bonding are aspects of breast-feeding enjoyed by WIC mothers in Hawaii that could be used in breast-feeding promotion efforts.

Geographic patterns of low birth weight in Hawaii.

This study examines areal variations in low birth weight, using the census tract as the unit of analysis. Reports from the 1980 U.S. census were used to develop summary indicators of environmental and socio-economic conditions, including poverty, employment, education and crowding, for 155 census tracts in the state of Hawaii. Maternal socio-demographic, prenatal care utilization, and medical risk indicators and low birth weight percentages for resident, single live births were extracted from the Hawaii 1979-1987 vital record live birth files and aggregated by census tract. Multiple regression analysis was used to develop a model that predicted 61% of the variation among census tracts in the percentage of low birth weight. Patterns of low birth weight were primarily associated with ethnic patterns of maternal residence and single marital status. There was no association between inadequate prenatal care and low birth weight at the census tract level.

Stroke in a patient with hemolytic-uremic syndrome with a good outcome.

We report a child with HUS complicated by stupor, hemiparesis, expressive aphasia and focal seizures. CAT scan of the brain demonstrated 2 large cerebral non-hemorrhagic infarcts. Despite the severe neurological involvement the child eventually made a good recovery.

Area-level predictors of use of prenatal care in diverse populations.

Patterns and predictors of the use of prenatal care in Hawaii were examined by census tract, taking into account summary measures of socioeconomic status, environmental conditions, and aggregated indicators of pregnancy-related risk characteristics of mothers. The objectives of the study were to identify those census tracts with high levels of inadequate use of prenatal care services; to develop a model, based on census tract characteristics, to explain observed geographic variations in the use of prenatal care services; and to identify for further investigation specific localities with unanticipated patterns of use. Data were drawn from 1980 census reports and vital statistics live birth files for the period 1979-87. Regression analysis was used to develop a model that was able to predict 61 percent of the census tract variation in the percentages of inadequate use of prenatal care services. Increased proportions of mothers of Japanese and other Asian-descent and of adults with more than high school education were associated with low levels of inadequate use of prenatal care services. Increased proportions of high parity-for-age risk and Samoan mothers were associated with higher levels of inadequate use. Census tract maps of actual and predicted percentages and studentized residual values were used to identify areas with high and low rates of inadequate use of prenatal care services. The area-level methods used are believed applicable to health care planning in other areas with ethnically or socioculturally diverse populations.

Birth outcomes of Korean women in Hawaii.

Since the end of the Korean War, immigration of Koreans to the United States has increased rapidly. In 1990, 11.6 percent of all Asians in the United States were of Korean ethnicity, and it is projected that Koreans will outnumber all other Asian groups, except Filipinos, in the United States by the year 2030. Despite the growing size of this population, very little is known about their health status. This study, using 1979-89 Hawaii vital record data, investigates the relationship between maternal sociodemographic characteristics, prenatal care utilization factors, and birth outcomes among Koreans as compared with Caucasians. The ethnic term "Caucasian" is used in Hawaii's vital records and is synonymous with non-Hispanic whites. Korean mothers were more likely to be older and have lower educational attainment, and less likely to be adolescent, single, or to have received adequate prenatal care than Caucasian mothers. More than 80 percent of the Korean mothers were foreign born. Significantly higher risks for very preterm delivery (less than 33 weeks) and very low birth weight births were observed for Koreans as compared with Caucasians. Nativity had no effect on birth outcome in this population. The results of this study suggest that prevention of preterm birth is an important focus for improving pregnancy outcomes in this growing ethnic group.

Discordance between LMP-based and clinically estimated gestational age: implications for research, programs, and policy.

This study examines the comparability between the last menstrual period-based and clinically estimated gestational age as collected on certificates of live birth. It explores whether sociodemographic or delivery characteristics influence their agreement and contrasts health status and health care utilization indicators, such as preterm, small for gestational age, and adequacy of prenatal care percentages, produced by each gestational age measure. The 1989-91 South Carolina public use live birth files were used for this analysis. A total of 169,082 single births to resident mothers were selected for investigation. The clinically estimated gestational age distribution exhibited a higher mean and a tendency toward even number digit preference. The last menstrual period-based measure produced higher preterm and postterm percentages. More than 60 percent of the last menstrual period-based preterm births were classified as preterm by the clinical estimate. The sensitivity of the clinical estimate was 27 percent for postterm births. The overall concordance (the percentage of cases with the same value for both measures) was 47 percent, but it varied considerably by gestational age. Between 30 and 35 weeks, the clinical estimate exceeded the last menstrual period-based value by 2 weeks or more for more than 40 percent of the cases. Concordance also varied by race of mother, hospital delivery size, trimester prenatal care began, and birth weight. The last menstrual period-based and the clinically estimated gestational age distributions exhibited notable dissimilarities, produced marked differences in health status indicators, and varied in concordance by gestational age and by sociodemographic, prenatal care, and hospital characteristics. These systematic differences suggest that a transition from the traditionally used last menstrual period-based measure to the clinical estimate or a composite measure will not produce uniform results across geo-political areas and at-risk groups but will be appreciably influenced by population and health care characteristics.

Temporal trends in maternal characteristics and pregnancy outcomes: their relevance to the provision of health services. Hawaii, 1979-1994.

This paper examines changes in maternal sociodemographic characteristics and pregnancy outcomes in Hawaii during the period 1979-1994. The more striking changes were increases of 129% in the proportion of births to women > 35 years old and of 67% in the proportion of births to unmarried mothers. The percentage of low birth weight and small-for-gestational age infants decreased while the proportion of premature births increased. Identified changes were not limited to selected population groups, but were found in various degrees in all ethnic groups. These findings are relevant to all health practitioners and will assist in the provision of appropriate care and counseling to individual women.

Prenatal care utilization in Hawaii: did it improve during the last 16 years?

This paper examines the utilization of prenatal care in Hawaii from 1979 to 1994 to determine if early and adequate utilization of prenatal care has changed during this period. Birth certificates of single live born infants of resident women were the source of data for the study. During the study period, the proportion of women receiving prenatal care in the first trimester increased by nearly 5 percent but was still below the national and state Year 2000 health objective of 90 percent. Notwithstanding this improvement, the percentage of women who did not receive the recommended number of visits in spite of starting care early significantly increased. The overall proportion of women with 'intensive' prenatal care use markedly increased (134.7%). The proportion of women with 'inadequate' care use declined (10.3%), although the proportion of women with 'no care' use doubled. Complete reporting of use of care through birth certificates markedly deteriorated. The findings of this study indicate the need for changes in the targeting and provision of counseling and education on the part of health care providers. Public health leaders, policy makers, health care providers, and advocacy groups need to collectively review programmatic directions with an aim toward the development of innovative approaches to address the emerging health needs of mothers and infants in the state.