Commercial Wet-Spun Singlewall and Dry-Spun Multiwall Carbon Nanotube Fiber Surface O-Functionalization by Ozone Treatment.

In this work, we demonstrate controlled introduction of O-functional groups on commercial carbon nanotube fibers (CNTFs) with different nanotube morphologies obtained by dry- and wet-spinning by treatment with gaseous ozone (O3(g)). Our test samples were (1) wet-spun fibers of smalldiameter (1-2 nm) singlewall (SW)-CNTs and (2) dry-spun fibers containing large-diameter (20 nm) multiwall (MW)-CNTs. Our results indicate that SW-CNTFs undergo oxygenation to a higher extent than MW-CNTFs due to the higher reactivity of SW-CNTs with a larger curvature strain. Oxygenation resulting from O3 exposure was evidenced as increase in surface O atomic% (at% by X-ray photoelectron spectroscopy, XPS) and as reductions in G/D (by Raman spectroscopy) as well as electrical conductivities due to changes in nanotube graphitic structure. By XPS, we identified the emergence of various types of O-functionalities on the fiber surfaces. After long duration O3 exposure (>300 s for SW-CNTFs and >600 s for MW-CNTFs), both sp² C═O (carbonyl) and sp³ C-O moieties (ether/hydroxy) were observed on fiber surfaces. Whereas, only sp³ C-O (ether/hydroxy) components were observed after shorter exposure times. O3 treatment led to only changes in surface chemistry, while the fiber morphology, microstructure and dimensions remained unaltered. We believe the surface chemistry controllability demonstrated here on commercial fibers spun by different methods containing nanotubes of different structures is of significance in aiding the practical application development of CNTFs.

Copper/carbon nanotube composites: research trends and outlook.

We present research progress made in developing copper/carbon nanotube composites (Cu/CNT) to fulfil a growing demand for lighter copper substitutes with superior electrical, thermal and mechanical performances. Lighter alternatives to heavy copper electrical and data wiring are needed in automobiles and aircrafts to enhance fuel efficiencies. In electronics, better interconnects and thermal management components than copper with higher current- and heat-stabilities are required to enable device miniaturization with increased functionality. Our literature survey encouragingly indicates that Cu/CNT performances (electrical, thermal and mechanical) reported so far rival that of Cu, proving the material's viability as a Cu alternative. We identify two grand challenges to be solved for Cu/CNT to replace copper in real-life applications. The first grand challenge is to fabricate Cu/CNT with overall performances exceeding that of copper. To address this challenge, we propose research directions to fabricate Cu/CNT closer to ideal composites theoretically predicted to surpass Cu performances (i.e. those containing uniformly distributed Cu and individually aligned CNTs with beneficial CNT-Cu interactions). The second grand challenge is to industrialize and transfer Cu/CNT from lab bench to real-life use. Toward this, we identify and propose strategies to address market-dependent issues for niche/mainstream applications. The current best Cu/CNT performances already qualify for application in niche electronic device markets as high-end interconnects. However, mainstream Cu/CNT application as copper replacements in conventional electronics and in electrical/data wires are long-term goals, needing inexpensive mass-production by methods aligned with existing industrial practices. Mainstream electronics require cheap CNT template-making and electrodeposition procedures, while data/electrical cables require manufacture protocols based on co-electrodeposition or melt-processing. We note (with examples) that initiatives devoted to Cu/CNT manufacturing for both types of mainstream applications are underway. With sustained research on Cu/CNT and accelerating its real-life application, we expect the successful evolution of highly functional, efficient, and sustainable next-generation electrical and electronics systems.

Valproate-Induced Polycystic Ovary Syndrome in a Girl with Epilepsy: A Case Study.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common ovulatory disorder that can be induced by sodium valproate (VPA). PATIENT: We report a case of PCOS that developed in a 15-year-old girl with idiopathic epilepsy after she took VPA. VPA administration stopped her seizures, but it also led to weight gain and amenorrhea, and the patient was diagnosed with PCOS on the basis of diagnostic imaging and serological examination results. Cessation of VPA administration led to reduced weight gain and restored menstruation. CONCLUSIONS: The risk of PCOS developing in patients with epilepsy is known to be high, and the association of VPA with PCOS is well established, so if physicians feel this is the best drug to prescribe for female patients with epilepsy, they should carefully monitor the patients' weight and menstruation, and immediately perform ovarian imaging and hormonal examinations if any abnormalities are observed.

Cervical Dilatation Curves of Spontaneous Deliveries in Pregnant Japanese Females.

Background: Although cervical dilatation curves are crucial for appropriate management of labor progression, abnormal labor progression and obstetric interventions were included in previous and widely-used cervical dilatation curves. We aimed to describe the cervical dilatation curves of normal labor progression in pregnant Japanese females without abnormal labor progression and obstetric interventions. Methods: We completed retrospective obstetric record reviews on 3172 pregnant Japanese females (parity = 0, n = 1047; parity = 1, n = 1083; parity ≥ 2, n = 1042), aged 20 to 39 years old at delivery, with pregravid body mass indices of less than 30. All patients underwent spontaneous deliveries with term, singleton, cephalic and live newborns of appropriate-for-gestational age birthweight, without adverse neonatal outcomes. We characterized labor progression patterns by examining the relationship between elapsed times from the full dilatation and cervical dilatation stages, and labor durations by examining the distribution of time intervals from one cervical dilatation stage, to the next, and ultimately to the full dilatation. Results: Fastest cervical changes occurred at 6 cm (primiparas) and 5 cm (multiparas) of dilatation. The 95%tile of labor progression took over 3 hours to progress from 6 cm to 7 cm (primiparas), and over 2 hours to progress from 5 cm to 6 cm (multiparas). The 5%tile of traverse time to the full dilatation, during the active phase, was less than 1 hour (primiparas) and 0.5 hours (multiparas). At the end of the active phase, no deceleration phase was observed. Conclusions: Active labor may not start until 5 cm of dilatation. At the beginning of the active phase, cervical dilatation was slower than previously described. These results may reduce opportunities for obstetric interventions during labor progression.

Electrical performance of lightweight CNT-Cu composite wires impacted by surface and internal Cu spatial distribution.

We report ultralong conducting lightweight multiwall carbon nanotube (MWCNT)-Cu composite wires with MWCNTs uniformly distributed in a continuous Cu matrix throughout. With a high MWCNT vol% (40-45%), the MWCNT-Cu wire density was 2/3rd that of Cu. Our composite wires show manufacturing potential because we used industrially compatible Cu electrodeposition protocols on commercial CNT wires. Further, we systematically varied Cu spatial distribution on the composite wire surface and bulk and measured the associated electrical performance, including resistivity (ρ), temperature dependence of resistance, and stability to current (measured as current carrying capacity, CCC in vacuum). We find that a continuous Cu matrix with homogeneous MWCNT distribution, i.e., maximum internal Cu filling within MWCNT wires, is critical to high overall electrical performances. Wires with maximum internal Cu filling exhibit (i) low room temperature ρ, 1/100th of the starting MWCNT wires, (ii) suppressed resistance-rise with temperature-increase and temperature coefficient of resistance (TCR) ½ that of Cu, and (iii) vacuum-CCC 28% higher than Cu. Further, the wires showed real-world applicability and were easily soldered into practical circuits. Hence, our MWCNT-Cu wires are promising lightweight alternatives to Cu wiring for weight-reducing applications. The low TCR is specifically advantageous for stable high-temperature operation, e.g., in motor windings.

Pregnancy-associated Deaths: 31-year Experience.

AIM: The aim of the present study was to elucidate the clinical characteristics of pregnancy-associated maternal deaths. METHODS: We performed a retrospective analysis with medical records and autopsy reports of cases of pregnancy-associated deaths. We collected information on all maternal deaths related to pregnancy that occurred in 3 hospitals affiliated with Nippon Medical School in Japan from January 1, 1984, to December 31, 2014. Data analyzed were maternal age, past medical history, parity, gestational age, clinical signs and symptoms, cause of death, and maternal autopsy findings. RESULTS: A total of 26 maternal deaths occurred during the 31-year study period. Autopsies were performed for 16 patients (61.5%). The 26 deaths included 19 (73.1%) classified as direct maternal deaths and 7 (26.9%) classified as indirect maternal deaths. The mean maternal age at death was 33.1±4.3 years (range, 26-41 years). The highest percentage of women was aged 35 to 39 years (38.5%). Of the 26 maternal deaths, 69% occurred at 32 to 41 weeks of gestation. In cases of direct maternal death, the leading causes were amniotic fluid embolism (7 cases, 27.0% of all deaths) and hemorrhage (6 cases, 23.1% of all deaths). In cases of indirect obstetric deaths, the causes included cardiovascular disorders, cerebrovascular disorders, sepsis due to group A streptococcal infection, and hepatic failure of unknown etiology. CONCLUSIONS: Amniotic fluid embolism was the leading cause of maternal deaths and was followed by obstetric hemorrhage. To prevent and reduce the number of maternal deaths in Japan, further basic and clinical research on amniotic fluid embolism is required.

A phenomenological model for selective growth of semiconducting single-walled carbon nanotubes based on catalyst deactivation.

A method for the selective semiconducting single-walled carbon nanotube (SWCNT) growth over a continuous range from 67% to 98%, within the diameter range of 0.8-1.2 nm, by the use of a "catalyst conditioning process" prior to growth is reported. Continuous control revealed an inverse relationship between the selectivity and the yield as evidenced by a 1000-times difference in yield between the highest selectivity and non-selectivity. Further, these results show that the selectivity is highly sensitive to the presence of a precise concentration of oxidative and reductive gases (i.e. water and hydrogen), and the highest selectivity occurred along the border between the conditions suitable for high yield and no-growth. Through these results, a phenomenological model has been constructed to explain the inverse relationship between yield and selectivity based on catalyst deactivation. We believe our model to be general, as the fundamental mechanisms limiting selective semiconducting SWCNT growth are common to the previous reports of limited yield.

Nano-scale, planar and multi-tiered current pathways from a carbon nanotube-copper composite with high conductivity, ampacity and stability.

New lithographically processable materials with high ampacity are in demand to meet the increasing requirement for high operational current density at high temperatures existing in current pathways within electronic devices. To meet this demand, we report an approach to fabricate a high ampacity (∼100 times higher than Cu) carbon nanotube-copper (CNT-Cu) composite into a variety of complex nano-scale, planar and multi-tiered current pathways. The approach involved the use of a two-stage electrodeposition of copper into a pre-patterned template of porous, thin CNT sheets acting as the electrode. The versatility of this approach enabled the realization of completely suspended multi-tier, dielectric-less 'air-gap' CNT-Cu circuits that could be electrically isolated from each other and are challenging to fabricate with pure Cu or any metal. Importantly, all such complex structures, ranging from 500 nm to 20 µm in width, exhibited ∼100-times higher ampacity than any known metal, with comparable electrical conductivity as Cu. In addition, CNT-Cu structures also exhibited a superior temperature stability compared to the ∼10-times wider Cu counterparts. We believe that the combination of our approach and the properties demonstrated here are vital achievements for the future development of efficient and powerful electrical devices.

Robust and Soft Elastomeric Electronics Tolerant to Our Daily Lives.

Clothes represent a unique textile, as they simultaneously provide robustness against our daily activities and comfort (i.e., softness). For electronic devices to be fully integrated into clothes, the devices themselves must be as robust and soft as the clothes themselves. However, to date, no electronic device has ever possessed these properties, because all contain components fabricated from brittle materials, such as metals. Here, we demonstrate robust and soft elastomeric devices where every component possesses elastomeric characteristics with two types of single-walled carbon nanotubes added to provide the necessary electronic properties. Our elastomeric field effect transistors could tolerate every punishment our clothes experience, such as being stretched (elasticity: ∼ 110%), bent, compressed (>4.0 MPa, by a car and heels), impacted (>6.26 kg m/s, by a hammer), and laundered. Our electronic device provides a novel design principle for electronics and wide range applications even in research fields where devices cannot be used.

Consecutive cervical length measurements as a predictor of preterm cesarean section in complete placenta previa.

BACKGROUND: To evaluate whether consecutive cervical length measurements can predict preterm cesarean section in women with complete placenta previa. METHODS: Seventy-one women with complete placenta previa were retrospectively categorized into women who delivered preterm due to massive hemorrhage (the preterm cesarean section group, n = 28) and those delivered at term (the control group, n = 43). Maternal characteristics, delivery outcomes, and cervical lengths serially measured at least every 2 weeks from 24 weeks' gestation until delivery were compared. The relationship between cervical length and preterm cesarean section was analyzed. RESULTS: Cervical length gradually decreased with advancing gestational age. After 26 weeks' gestation, this decrease was significantly more rapid in the preterm cesarean section group. Cervical length before cesarean section in the preterm cesarean section group was significantly shorter than that in the control group. Just before cesarean section, 71.4% of the preterm cesarean section group presented with cervical lengths of ≤35 mm, whereas only 34.9% of the control group had cervical lengths of ≤35 mm (odds ratio 4.67, 95% confidence interval 1.66-13.10, p = 0.006). CONCLUSIONS: In women with complete placenta previa, decrease in cervical length to ≤35 mm was associated with increased risk of preterm cesarean section due to massive hemorrhage.

Safety of induced abortions at less than 12 weeks of pregnancy in Japan.

OBJECTIVE: To assess the safety of various methods of induced abortion when used before 12 weeks of pregnancy in Japan. METHODS: A retrospective study was undertaken of induced abortions conducted between January 1 and December 31, 2012. Questionnaires were sent to 4154 institutions that employed doctors who were licensed to conduct induced abortions. Information was obtained about the numbers of induced abortions performed before 12 weeks, methods, complications, and routine management. RESULTS: Completed questionnaires from 2434 institutions showed that 100 851 induced abortions had been performed. Vacuum aspiration (VA) was used in 20 458 (20.3%) abortions, VA with sharp curettage in 47 148 (46.8%), dilatation and curettage (D&C) in 32 958 (32.7%), and medical abortion in 287 (0.3%). Overall, 358 complications were reported (355.0 per 100000 procedures). The rate of complications was significantly higher after D&C than after VA and after VA with sharp curettage (P<0.001 for both). However, incomplete abortion requiring repeat procedures was the only complication that was significantly associated with D&C (P<0.001). CONCLUSION: D&C can be safely used for induced abortion before 12 weeks of pregnancy, but changing from D&C to VA could reduce incomplete abortions and improve the safety of induced abortions before 12 weeks of pregnancy in Japan.

Clinical characteristics of amniotic fluid embolism: an experience of 29 years.

AIM: The aim of this study was to elucidate the clinical characteristics and risk factors for amniotic fluid embolism (AFE). METHODS: We performed a retrospective case study analysis of patients using medical records and autopsy records. The diagnosis of AFE was based on the presence of clinical symptoms using Clark's criteria and autopsy results. We analyzed patient records from a 29-year period in three hospitals affiliated with the Nippon Medical School in Japan. RESULTS: Ten diagnoses of AFE were found in the records. First, we classified AFE patients into two types based on the initial presenting symptoms: post-partum hemorrhage and cardiopulmonary collapse. Fifty percent of the patients initially presented with post-partum hemorrhage and disseminated intravascular coagulation. Most were diagnosed with post-partum hemorrhage or uterine atony at AFE onset. Similarly, 50% presented with cardiopulmonary arrest or pulmonary arrest as initial symptoms, and most were diagnosed with eclampsia. Second, risk factors for AFE included advanced maternal age, multiparity, increased intrauterine pressure and disruptions of the uterine vasculature. Third, the case fatality rate was 70%. Fourth, squamous cells were observed in maternal central venous blood of five patients. CONCLUSION: AFE patients were classified into two types based on presenting signs and symptoms. Knowledge of the various initial symptoms of AFE enables a correct diagnosis.

Bifid scrotum and anocutaneous fistula associated with a perineal lipomatous tumor complicated by temporary bilateral cryptorchidism in utero mimicking ambiguous genitalia: 2-D/3-D fetal ultrasonography.

Ambiguous genitalia (AG) is a morphological diagnosis defined as genitalia not typical of a male or female. Findings mimicking AG, such as penoscrotal anomalies, anorectal malformations, and perineal lipomatous tumors, may prevent accurate identification of the fetal sex. We report a case of bifid scrotum and anocutaneous fistula associated with a perineal lipomatous tumor complicated by temporary bilateral cryptorchidism in utero, which were findings mimicking AG. Several perineal anomalies are associated developmental occurrences. In the present case, the combination of bifid scrotum and temporary bilateral cryptorchidism in the male fetus mimicked the combination of clitoromegaly and prominent labia, which are commonly observed in female fetuses. However, serial systemic assessments using prenatal 2-D/3-D ultrasonography and magnetic resonance imaging were unable to detect the anocutaneous fistula and differentiate the perineal lipomatous tumor. This case report suggests that the prenatal detection of perineal abnormalities may warn obstetricians of potentially undetected congenital perineal anomalies.

Type and location of placenta previa affect preterm delivery risk related to antepartum hemorrhage.

PURPOSE: To evaluate whether type and location of placenta previa affect risk of antepartum hemorrhage-related preterm delivery. METHODS: We retrospectively studied 162 women with singleton pregnancies presenting placenta previa. Through observation using transvaginal ultrasound the women were categorized into complete or incomplete placenta previa, and then assigned to anterior and posterior groups. Complete placenta previa was defined as a placenta that completely covered the internal cervical os, with the placental margin >2 cm from the os. Incomplete placenta previa comprised marginal placenta previa whose margin adjacent to the internal os and partial placenta previa which covered the os but the margin situated within 2 cm of the os. Maternal characteristics and perinatal outcomes in complete and incomplete placenta previa were compared, and the differences between the anterior and the posterior groups were evaluated. RESULTS: Antepartum hemorrhage was more prevalent in women with complete placenta previa than in those with incomplete placenta previa (59.1% versus 17.6%), resulting in the higher incidence of preterm delivery in women with complete than in those with incomplete placenta previa [45.1% versus 8.8%; odds ratio (OR) 8.51; 95% confidence interval (CI) 3.59-20.18; p < 0.001]. In complete placenta previa, incidence of antepartum hemorrhage did not significantly differ between the anterior and the posterior groups. However, gestational age at bleeding onset was lower in the anterior group than in the posterior group, and the incidence of preterm delivery was higher in the anterior group than in the posterior group (76.2% versus 32.0%; OR 6.8; 95% CI 2.12-21.84; p = 0.002). In incomplete placenta previa, gestational age at delivery did not significantly differ between the anterior and posterior groups. CONCLUSION: Obstetricians should be aware of the increased risk of preterm delivery related to antepartum hemorrhage in women with complete placenta previa, particularly when the placenta is located on the anterior wall.

One hundred fold increase in current carrying capacity in a carbon nanotube-copper composite.

Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube-copper composite exhibiting similar conductivity (2.3-4.7 × 10(5) S cm(-1)) as copper (5.8 × 10(5) S cm(-1)), but with a 100-times higher ampacity (6 × 10(8) A cm(-2)). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (~2.0 eV) in carbon nanotube-copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters.

Ultrasound detection of lacunae-like image of a cesarean scar pregnancy in the first trimester.

Cesarean scar pregnancy is one of the rare types of ectopic pregnancy. Ultrasonography enables early diagnosis and the successful preservation of the uterus. However, the correct diagnosis of cesarean scar pregnancy can be difficult in some cases. We describe a case of cesarean scar pregnancy that was initially misdiagnosed on the basis of current ultrasonographic criteria. Ultrasonographic images at 9 weeks' gestation demonstrated no gestational sac but did show a bulging mass in uterine wall with irregularly shaped hypoechoic areas, which resembled the lacunae in placenta previa. Color Doppler imaging demonstrated that the lacunae-like areas were richly perfused. Cesarean scar pregnancy was finally diagnosed with magnetic resonance imaging, which showed a lack of myometrium in the lower anterior uterine wall with placental invasion. Histological examination of the uterus after hysterectomy revealed the direct invasion of trophoblasts into the mural zone which had resulted in a deficit of myometrium at the previous cesarean scar. A mass in the myometrium with richly perfused lacunae-like areas should be considered as one of the important ultrasonographic findings indicating cesarean scar pregnancy.

Torsion-sensing material from aligned carbon nanotubes wound onto a rod demonstrating wide dynamic range.

A rational torsion sensing material was fabricated by wrapping aligned single-walled carbon nanotube (SWCNT) thin films onto the surface of a rod with a predetermined and fixed wrapping angle without destroying the internal network of the SWCNTs within the film. When applied as a torsion sensor, torsion could be measured up to 400 rad/meter, that is, more than 4 times higher than conventional optical fiber torsion sensors, by monitoring increases in resistance due to fracturing of the aligned SWCNT thin films.

"Double eyes" sign of congenital bilateral dacryocystoceles.

Dacryocystocele is caused by nasolacrimal duct obstruction and results in cystic dilatation of the proximal part of the nasolacrimal duct, which is located inferomedial to the orbit, leading to fluid accumulation. It is important to consider that persistent congenital bilateral dacryocystoceles may cause neonatal nasal obstruction resulting in respiratory difficulty, and large dacryocystoceles may require surgical drainage. Ultrasonography demonstrates that congenital bilateral dacryocystoceles and normal eyeballs prenatally resemble two pairs of cystic "lesions" of different sizes. We herein present a case of prenatally diagnosed isolated congenital bilateral dacryocystoceles and propose the new name of "double eyes" sign for this rare condition to create an impact on medical students and residents.

Morphological changes observed via fetal ultrasound in prenatally diagnosed and isolated congenital lymphangiomas: three case reports.

We illustrate three cases of isolated congenital lymphangioma (CL). Fetal ultrasound (US) demonstrated uniloculated cystic masses that changed to multiloculated, subcutaneous, hypoechoic, avascular cystic masses with thin septations without solid components. Case 1: CL of the right forearm; Case 2: CL of the right hypochondrium; and Case 3: CL of the left upper posterior back. Postnatal US detected multiloculated, subcutaneous, hypoechoic, avascular cystic masses with thin septations without solid components or invasive developments. We prenatally and postnatally diagnosed them as isolated CL cases due to focal, soft, bulging masses with unclear margins. Due to our correct diagnosis and precise evaluation of sizes and locations, no perinatal complications occurred. In this case series, uniloculated features changed to multiloculated features and the largest macrocyst size decreased, whereas the sizes of the smaller microcysts increased. These morphological changes observed via fetal US represent intermittent CL growing processes.