Uterine cervical conisation and chorioamnionitis: A nationwide observational study.

OBJECTIVE: To investigate whether conisation increases chorioamnionitis (CAM) and assess whether this risk differs between preterm and term periods. Furthermore, we estimated mediation effects of CAM between conisation and preterm birth (PTB). DESIGN: A nationwide observational study. SETTING: Japan. POPULATION: Singleton pregnant women derived from the perinatal registry database of the Japan Society of Obstetrics and Gynaecology between 2013 and 2019. METHODS: The association between a history of conisation and clinical CAM was examined using a multivariable logistic regression model with multiple imputation. We conducted mediation analysis to estimate effects of CAM on PTB following conisation. MAIN OUTCOME MEASURES: Clinical CAM. RESULTS: Of 1 500 206 singleton pregnant women, 6961 (0.46%) underwent conisation and 1 493 245 (99.5%) did not. Clinical CAM occurred in 150 (2.2%) and 11 484 (0.8%) women with and without conisation, respectively. Conisation was associated with clinical CAM (odds ratio [OR] 3.09; 95% confidence interval (CI) 2.63-3.64; p < 0.001) (risk difference 1.57%; 95% CI 1.20-1.94). The association was detected among 171 440 women with PTB (OR 3.09; 95% CI 2.57-3.71), whereas it was not significant among 1 328 284 with term birth (OR 0.88; 95% CI 0.58-1.34). OR of total effect of conisation on PTB was 2.71, OR of natural indirect effect (effect explained by clinical CAM) was 1.04, and OR of natural direct effect (effect unexplained by clinical CAM) was 2.61. The proportion mediated was 5.9%. CONCLUSIONS: Conisation increased CAM occurrence. Obstetricians should be careful regarding CAM in women with conisation, especially in preterm period. Bacterial infections may be an important cause of PTB after conisation.

Species cohesion of an extremophyte (Carex angustisquama, Cyperaceae) in solfatara fields maintained under interspecific natural hybridization.

BACKGROUND AND AIMS: Hybridization is the main driver of plant diversification, and gene flow via hybridization has multifaceted effects on plant evolution. Carex angustisquama is an extremophyte that grows on soils heavily acidified by volcanism. Despite its habitat distinct from that of other species, this species is known to form interspecific hybrids, implying interspecific gene flow. It is crucial to verify the extent and direction of interspecific gene flow between C. angustisquama and closely related species to understand the evolutionary process of an extremophyte in solfatara fields. METHODS: In this study, expressed sequence tag-simple sequence repeat markers were utilized to infer the extent and direction of interspecific gene flow between C. angustisquama and closely related species. KEY RESULTS: Bayesian clustering and simulation analyses revealed that all individuals of the three hybrid species were classified into the first hybrid generation or first backcross to C. angustisquama; therefore, current interspecific gene flow is limited. Moreover, in the Bayesian inference of historical gene flow based on multispecies samples, the model that assumed no interspecific gene flow was the most strongly supported across all species pairs, including phylogenetically close but ecologically distinctive species pairs. CONCLUSIONS: Our results revealed that interspecific gene flow between C. angustisquama and its related species has been limited both currently and historically. Moreover, our results of Bayesian inference of historical gene flow indicated that extrinsic, rather than intrinsic, factors probably act as isolating barriers between Carex species, with hybrid breakdown via microhabitat segregation being the probable potential barrier. Overall, our findings provide insights into the evolutionary process of an extremophyte in solfatara fields and offer an important example of the mechanisms of diversification of the speciose genus Carex.

Takotsubo syndrome occurring concomitantly with pre-eclampsia: A case report.

Takotsubo syndrome (TTS) patients show transient ventricular dysfunction without coronary artery stenosis. We report a pregnant woman with TTS occurring concomitantly with severe pre-eclampsia (PE). A primiparous woman complained of dyspnea at 35 weeks of gestation. She showed severe PE, and cardiac ultrasound identified akinesis of the anterior lower wall. On the same day, emergent cesarean section was performed due to a nonreassuring fetus status, yielding a male infant with an umbilical artery pH of 6.851. Unfortunately, the neonate died of multiple organ failure. Following the delivery, her cardiac function markedly improved, and coronary angiography showed no coronary artery stenosis. Considering the clinical findings, we diagnosed the patient with TTS. Regarding antenatally occurring TTS, only six patients have been reported including the present one. Of the six patients, three had severe PE. Although previous reports on pregnancy-associated TTS described good maternal outcomes, antenatally occurring TTS complicated by severe PE may become critical for fetuses.

Fetal seizure: A video recording and possible etiology.

Fetal seizure is rarely observed. Investigation of both video-recording of seizures and cardiotocography is crucial for a precise diagnosis. Here, we report a case of fetal seizure, and also show a video-ultrasound recording. A 40-year-old woman was admitted to us due to loss of variability in cardiotocography. Ultrasound repeatedly revealed opisthotonus-like and clonic-seizure-like movements. After the abnormal movement, tachycardia up to 210 bpm (postictal tachycardia) was noted. Ultrasound revealed a nuchal cord. A careful investigation of video-ultrasound recording by an epilepsy specialist led to the confirmation of epileptic seizures. At 364/7 , she vaginally gave birth to an infant with an umbilical artery pH of 7.22. The infant died 30 min after birth. No clear video-recordings associated with fetal seizure were available for cases reported so far in the literature. The video provided in this case may be of use for further analyses.

Matsubara-Yano suture: a simple uterine compression suture for postpartum hemorrhage during cesarean section.

AIMS: The aims of this study were to clarify: (i) the effectiveness of Matsubara-Yano uterine compression suture (MY) to achieve hemostasis in the presence of postpartum hemorrhage (PPH) during cesarean section, (ii) the type of PPH for which MY is effective, (iii) post-operative complications of MY, and (iv) outcomes of pregnancy after MY. METHODS: This retrospective observational study was performed using medical records of patients for whom MY had been performed between January 1, 2009 and December 31, 2017. RESULTS: MY was performed for 50 patients, with hemostasis achieved in 46 (92%). The other four (8%: 4/50) patients required transarterial embolization or hysterectomy. Of these four, three patients had placenta accreta spectrum (PAS) disorder-related bleeding. Post-operative complications were observed in three (6%: 3/50) patients, with all showing intrauterine infection. All three patients recovered solely with antibiotics. Eight pregnancies were confirmed (five livebirths, two spontaneous abortions in the first trimester, and one case of ongoing pregnancy). Of the five livebirths, one resulted in cesarean hysterectomy due to placenta previa with PAS disorders. CONCLUSIONS: MY had a hemostatic effect on PPH. All cases except one with hemostatic failure were associated with PAS disorders, indicating that the hemostatic rate was lower in those with PAS than non-PAS disorders.

Vaginal Ureaplasma species increase chorioamnionitis in very preterm infants with preterm premature rupture of the membranes at < 28 weeks of gestation.

Our aim was to investigate the association between vaginal Ureaplasma species (spp.) and the subsequent occurrence of chorioamnionitis (CAM), perinatal death, neonatal morbidity, and long-term neurodevelopmental impairments (NDIs) at 3 years of age. We analyzed 55 pregnant women with singleton pregnancy who had preterm premature rupture of the membranes (pPROM) at < 28+0 weeks of gestation, and delivered between 22+0 and 31+6 weeks at our tertiary hospital in 2007-2016. NDIs were defined as either cerebral palsy or developmental delay evaluated at 1.5 and/or 3 years old. The presence of Ureaplasma spp. and Mycoplasma hominis were evaluated using urea-arginine broth and Mycoplasma PPLO Agar. The presence of Ureaplasma spp. in the vagina was positive in 41%. Vaginal Ureaplasma spp. was a significant risk factor for CAM; however, it was not significantly associated with the occurrence of perinatal death, pulmonary hypoplasia, respiratory distress syndrome, transient tachypnea of the newborn, intraventricular hemorrhage, periventricular leukomalacia, bronchopulmonary dysplasia defined as oxygen required and occasional ventilatory assistance required at week 36 as modified (BPD36), or NDIs. The crude odds ratio (95% confidence interval) of Ureaplasma spp. for the occurrence of CAM was 9.5 (1.10-82) (p = 0.041). In very preterm birth infants with pPROM, CAM, BPD36, and NDIs occurred in 78, 60, and 36%, respectively. Vaginal Ureaplasma spp. was a significant risk factor for CAM in very preterm birth infants with pPROM. The incidences of BPD36 and NDIs in such infants were very high, nearing 3/5 and 1/3, respectively.

Simultaneous evaluation of the effects of geographic, environmental and temporal isolation in ecotypic populations of Solidago virgaurea.

Early stages of ecological speciation can create populations with an ecology and reproduction timing distinct from those of related populations. Landscape genetic models incorporating environmental heterogeneity and population-specific reproductive traits enable the processes of population genetic differentiation to be inferred. We investigated genome-wide genetic variation in ecotypic populations of Solidago virgaurea sensu lato, a herbaceous plant inhabiting a wide range of habitats (woodlands, serpentine barrens and alpine grasslands) and displaying remarkable variation in flowering time. Simultaneous evaluation of environmental factors revealed an overwhelming effect of soil type differences on neutral genetic differentiation, compared with elevational differences. This result probably reflects the abrupt environmental changes generated by geological boundaries, whereas mountain slopes exhibit clinal changes, facilitating gene exchange between neighbouring populations. Temporal isolation was positively associated with genetic differentiation, with some early-flowering serpentine populations having allele frequencies distinct from adjacent nonserpentine populations. Overall, this study highlights the importance of ecological processes and of evolution of flowering time to promote genetic differentiation of S. virgaurea populations in a complex landscape.

Color vision abnormality as the sole manifestation of posterior reversible encephalopathy due to post-partum HELLP syndrome.

Posterior reversible encephalopathy syndrome (PRES) is associated with several symptoms; of those, visual acuity loss, light oversensitivity (photophobia), and light flashes (photopsia) are known as PRES-related eye symptoms. We report a post-partum woman with PRES associated with hemolysis, elevated liver enzymes, and low platelets syndrome (HELLP), in whom color vision abnormality (achromatopsia) was the sole manifestation. Cesarean section was performed at 28 weeks due to headache, epigastralgia, and severe hypertension. HELLP became evident after delivery. On post-partum day 1, she complained of achromatopsia, stating: "all things look brownish-gray". Ophthalmologic examination was normal, but brain magnetic resonance imaging showed occipital lobe lesions, indicative of PRES, and, interestingly, also color vision center (area V4) lesions, suggesting that the achromatopsia had been caused by brain damage. It may be prudent to question HELLP patients concerning achromatopsia.

Thrombus just beneath a retrievable inferior vena cava filter in a pregnant woman with deep vein thrombosis: its removal requiring catheter thrombus fragmentation with fibrinolysis.

Recently, transient inferior vena cava (IVC) filters have been employed to protect against pulmonary embolism (PE) in pregnant women with deep vein thrombosis. A 34-year-old primiparous Japanese woman with a history of myomectomy was diagnosed with deep vein thrombosis by ultrasound at 27 weeks of gestation. Unfractionated heparin was administered, which soon ameliorated swelling in the right thigh. A transient IVC filter was implanted just before cesarean section. An enhanced computed tomography scan 2 days after cesarean section revealed a wide thrombus just distal to the filter. We performed catheter thrombus fragmentation with fibrinolysis just before the removal of the IVC filter, resulting in re-canalization of blood flow. No significant PE occurred. Although a transient IVC filter may work well for the prophylaxis of PE during labor and delivery, catheter fragmentation with fibrinolysis may become necessary at removal of the filter.

Clinical relevance of reversible cerebral vasoconstriction syndrome in pregnant women with posterior reversible encephalopathy syndrome: review of case reports in Japan.

We systematically reviewed case reports of posterior reversible encephalopathy syndrome (PRES), and investigated the characteristics of PRES in pregnant Japanese women and the clinical relevance of reversible cerebral vasoconstriction syndrome (RCVS) in pregnant women with PRES. Articles were collected using the PubMed/Medline and Ichushi-Web databases. This review was ultimately conducted on 121 articles (162 patients). The clinical characteristics of PRES, individual sites of PRES lesions, edema types, and clinical characteristics of RCVS in PRES cases were examined. The most common individual site of PRES lesion was the occipital lobe (83.3%), followed by the basal ganglia, parietal lobe, frontal lobe, brain stem, cerebellum, temporal lobe, thalamus, and splenium corpus callosum (47.5, 42.6, 24.7, 16.1, 9.3, 5.6, 4.3, and 0.0%, respectively). Edema types in 79 cases with PRES were mainly the vasogenic edema type (91.1%), with very few cases of the cytotoxic edema type (3.8%) and mixed type (5.1%). Among 25 PRES cases with RCVS, RCVS was not strongly suspected in 17 (68.0%) before magnetic resonance angiography. RCVS was observed at the same time as PRES in 13 cases (approximately 50%), and between days 1 and 14 after the onset of PRES in the other 12. These results suggest that the basal ganglia is a frequent site of PRES lesions in pregnant women. RCVS may occur at or after the onset of PRES, even if there are no symptoms to suggest RCVS.

A novel variant in IFT122 associated with a severe phenotype of cranioectodermal dysplasia.

A 27-year-old multiparous woman conceived her fetus naturally. Early second-trimester ultrasound showed short extremities with systemic subcutaneous edema. The pregnancy was artificially terminated at 19 weeks of gestation because of the abnormalities based on the parents' wishes. The parents desired whole-exome sequencing to detect a causative gene using the umbilical cord and the parents' saliva. Compound heterozygous variants (NC_000003.11(NM_052989.3):c.230 T > G/NC_000003.11(NM_052985.4):c.1178A > T) were identified. We described a fetus with a novel compound heterozygous variant in IFT122. The phenotype of this case was severer than of other types of cranioectodermal dysplasia.

Association between adenomyosis and placenta accreta and mediation effect of assisted reproductive technology on the association: A nationwide observational study.

OBJECTIVES: To investigate the association between adenomyosis and placenta accreta spectrum (PAS) and to evaluate the effect of assisted reproductive technology (ART) in mediating this association. METHODS: We retrieved data for singleton women from the Japanese nationwide perinatal registry between 2013 and 2019, excluding women with a history of adenomyomectomy. To investigate the association between adenomyosis and PAS among women, we used a multivariable logistic regression model with multiple imputation for missing data. We evaluated mediation effect of ART including in vitro fertilization and intracytoplasmic sperm injection on the association between adenomyosis and PAS using causal mediation analysis based on the counterfactual approach. RESULTS: Of 1 500 173 pregnant women, 1539 (0.10%) had adenomyosis. The number receiving ART was 489/1539 (31.8%) and 117 482/1 498 634 (7.8%) in women with and without adenomyosis, respectively. The proportion of women who developed PAS was 21/1539 (1.4%) in women with adenomyosis and 7530/1 498 634 (0.5%) in women without adenomyosis. Adenomyosis was significantly associated with PAS (odds ratio [OR] 1.95; 95% confidence interval [CI] 1.26-3.00; P = 0.002). Mediation analysis showed that OR of the total effect of adenomyosis on PAS was 1.98 (95% CI 1.13-3.04), OR of natural indirect effect (effect explained by ART) was 1.15 (95% CI 1.01-1.41), and OR of natural direct effect (effect unexplained by ART) was 1.72 (95% CI 0.86-2.82). The proportion mediated (natural indirect effect/total effect) was 26.5%. Adenomyosis was also significantly associated with PAS without previa (OR 1.96; 95% CI 1.23-3.13, P = 0.005). CONCLUSION: Adenomyosis was significantly associated with PAS. ART mediated 26.5% of the association between adenomyosis and PAS.

Automated electrochemiluminescence immunoassay for serum PlGF levels in women with singleton pregnancy at 9-13 weeks of gestation predicts preterm preeclampsia: a retrospective cohort study.

Our aims were to obtain the gestational-age-specific median of common logarithmic placental growth factor (PlGF) values in the first trimester in women with a singleton pregnancy in order to generate the gestational-age-specific multiple of the median (MoM) of log10PlGF at 9-13 weeks of gestation, to evaluate screening parameters of MoM of log10PlGF at 9-13 weeks of gestation to predict preterm preeclampsia (PE), and to construct an appropriate prediction model for preterm PE using minimum risk factors in multivariable logistic regression analyses in a retrospective sub-cohort study. Preterm PE occurred in 2.9% (20/700), and PE in 5.1% (36/700). Serum PlGF levels were measured using Elecsys PlGF®. MoMs of log10PlGF at 9-13 weeks of gestation in Japanese women with a singleton pregnancy followed a normal distribution. We determined the appropriate cut-off value of MoM of log10PlGF to predict preterm PE at around a10% false-positive rate (0.854). The MoM of log10PlGF < 0.854 yielded sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio (95% confidence interval [CI]), and negative likelihood ratio (95% CI) of 55.0%, 91.9%, 17.5%, 98.5%, 6.79 (4.22-10.91), and 0.49 (0.30-0.80), respectively. The combination of MoM of log10PlGF and presence of either chronic hypertension or history of PE/gestational hypertension (GH) yielded sensitivity and specificity of 80.0 and 85.7%, respectively, to predict preterm PE. In conclusion, the automated electrochemiluminescence immunoassay for serum PlGF levels in women with singleton pregnancy at 9-13 weeks of gestation may be useful to predict preterm PE.

"Invisible" radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant.

Understanding radioactive Cs contamination has been a central issue at Fukushima Daiichi and other nuclear legacy sites; however, atomic-scale characterization of radioactive Cs in environmental samples has never been achieved. Here we report, for the first time, the direct imaging of radioactive Cs atoms using high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In Cs-rich microparticles collected from Japan, we document inclusions that contain 27 - 36 wt% of Cs (reported as Cs2O) in a zeolite: pollucite. The compositions of three pollucite inclusions are (Cs1.86K0.11Rb0.19Ba0.22)2.4(Fe0.85Zn0.84X0.31)2.0Si4.1O12, (Cs1.19K0.05Rb0.19Ba0.22)1.7(Fe0.66Zn0.32X0.41)1.4Si4.6O12, and (Cs1.27K0.21Rb0.29Ba0.15)1.9(Fe0.60Zn0.32X0.69)1.6Si4.4O12 (X includes other cations). HAADF-STEM imaging of pollucite, viewed along the [111] zone axis, revealed an array of Cs atoms, which is consistent with a simulated image using the multi-slice method. The occurrence of pollucite indicates that locally enriched Cs reacted with siliceous substances during the Fukushima meltdowns, presumably through volatilization and condensation. Beta radiation doses from the incorporated Cs are estimated to reach 106 - 107 Gy, which is more than three orders of magnitude less than typical amorphization dose of zeolite. The atomic-resolution imaging of radioactive Cs is an important advance for better understanding the fate of radioactive Cs inside and outside of nuclear reactors damaged by meltdown events.

A new Early Cretaceous eutherian mammal from the Sasayama Group, Hyogo, Japan.

We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the 'Lower Formation' of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3-4 : 1 : 4 : 3, a robust lower canine, a non-molariform lower ultimate premolar, and a secondarily reduced entoconid on the molars. To date, S. kawaii is the earliest known eutherian mammal possessing only four premolars, which demonstrates that the reduction in the premolar count in eutherians started in the late Early Cretaceous. The occurrence of S. kawaii implies that the relatively rapid diversification of eutherians in the mid-Cretaceous had already started by the early Albian.

Uterine contraction may not be an independent risk factor for spontaneous preterm birth before 35 weeks in women with cervical shortening.

OBJECTIVE: To compare the risk of spontaneous preterm birth (SPTB) before 35 weeks in symptomatic and asymptomatic women with cervical shortening at 16-34 weeks under mid-trimester universal screening of cervical length (CL). METHOD: Multicenter retrospective cohort study involving six secondary/tertiary perinatal centers was planned in 2016. Primary outcomes were SPTB before 35 weeks. In all, 407 women were analyzed using multivariable logistic regression analysis for predicting SPTB before 35 weeks while adjusting for presence/absence of uterine contraction, gestational weeks, vaginal bleeding, and CL classification (1-9, 10-14, 15-19, and 20-24 mm) at admission, the execution of cervical cerclage, and the presence/absence of past history of preterm delivery. RESULTS: SPTB before 35 weeks of pregnancy occurred in 14.5%. Presence of uterine contraction was not an independent risk factor for SPTB before 35 weeks (adjusted odds ratio [aOR] 1.22, 95% confidence interval [CI] 0.67-2.20). CL of 1-9 mm, CL of 10-14 mm, and vaginal bleeding at admission were independent risk factors for SPTB before 35 weeks (aOR 5.35, 95% CI 2.11-13.6; aOR 2.79, 95% CI 1.12-6.98; and aOR 2.37, 95% CI 1.12-5.10, respectively). CONCLUSION: In women with a cervical shortening at 16-34 weeks, presence of uterine contractions at admission may not be an independent risk factor for the occurrence of SPTB before 35 weeks.

Occurrence of radioactive cesium-rich micro-particles (CsMPs) in a school building located 2.8 km south-west of the Fukushima Daiichi Nuclear Power Plant.

Radioactive Cs-rich microparticles (CsMPs) released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) are a potential health risk through inhalation. Little has been documented on the occurrence of CsMPs, particularly their occurrence inside buildings. In this study, we quantitatively analyze the distribution and number of CsMPs in indoor dust samples collected from an elementary school located 2.8 km to the southwest of FDNPP. The school had remained deserted until 2016. Then, using a modified version of the autoradiography-based "quantifying CsMPs (mQCP) method," we collected samples and determined the number of CsMPs and Cs radioactive fraction (RF) values of the microparticles (defined as total Cs activity from CsMPs/bulk Cs activity of the entire sample). The numbers of CsMPs ranged from 653 to 2570 particles/(g dust) and 296-1273 particles/(g dust) on the first and second floors of the school, respectively. The corresponding RFs ranged between 6.85 - 38.9% and 4.48-6.61%, respectively. The number of CsMPs and RF values in additional outdoor samples collected near the school building were 23-63 particles/(g dust or soil) and 1.14-1.61%, respectively. The CsMPs were most abundant on the school's first floor near to the entrance, and the relative abundance was higher near the stairs on the second floor, indicating a likely CsMP dispersion path through the building. Additional wetting of the indoor samples combined with autoradiography revealed that indoor dusts had a distinct absence of intrinsic, soluble Cs species, such as CsOH. These combined observations indicate that a significant amount of poorly soluble CsMPs were likely contained in initial radioactive airmass plumes from the FDNPP and that the microparticles penetrated buildings. CsMPs could still be abundant at the location, with locally high Cs activity in indoor environments near to openings.

Hemostatic effect of combined procedures for placenta previa: cervix-holding, intrauterine balloon, and uterine compression suture.

OBJECTIVES: Various procedures have been introduced to achieve hemostasis for postpartum hemorrhage (PPH) in placenta previa (PP). This study attempted to clarify the effectiveness of the combined use of three hemostatic procedures: Matsubara-Takahashi cervix-holding (MT-holding), intrauterine balloon (IUB), and uterine compression suture (UCS). STUDY DESIGN: This was a historical cohort study on the hemostatic effect of combined procedures for patients with placenta previa (PP) undergoing cesarean section between April 2006 and December 2018. Until 2011 (2006-2011), we used MT-holding alone, whereas since 2012 we have also been using IUB and UCS: MT-holding alone was used in the former period whereas three procedures (MT-holding, IUB, UCS, and their combinations) have been used in the latter period. Perinatal outcomes were compared between 2006-2011 (before group) and 2012-2018 (after group). RESULTS: Of 416 patients with PP, excluding 273 patients with cesarean hysterectomy or no hemostatic procedure, the remaining 143 patients were analyzed. In the after group, intraoperative blood loss, the percentage of patients with postoperative blood loss ≥ 500 ml, and incidence of autologous blood transfusion were significantly lower than in the before group. Multivariate analysis showed that postoperative blood loss ≥ 500 ml decreased in the after group (adjusted OR: 0.3, 95%CI: 0.1-0.8, compared with the before group). CONCLUSION: PPH decreased after introducing the combination of hemostatic procedures in patients with PP. Further studies are needed to determine the best combination and optimal indication for combining hemostatic procedures for PP.

Bleeding-related outcomes of low-risk total placenta previa are equivalent to those of partial/marginal placenta previa.

OBJECTIVE: To clarify whether "low-risk total PP" patients bleed more than partial/marginal PP patients. MATERIALS AND METHODS: The retrospective cohort study was performed involving patients with PP between April 2006 and December 2018. The placental position was determined by ultrasound. From medical charts, the backgrounds as well as obstetric and neonatal outcomes of PP patients were retrieved. RESULTS: This study included 349 patients with PP, which was classified into three types according to the distance between the placenta and internal ostium: total (n = 174), partial (n = 52), and marginal (n = 123) PP. In total PP patients, three factors (prior CS, anterior placenta, and placental lacunae on ultrasound) significantly increased blood loss at CS, the need for hysterectomy, homologous transfusion (≥10 U), and ICU admission. No significant difference was observed in bleeding-related poor outcomes (rate of blood loss ≥2000 mL, amount of homologous transfusion, need for hysterectomy, and ICU admission) between total PP patients without all three factors: "low-risk total PP patients" and partial/marginal PP patients (19.8 vs. 17.1%; p = 0.604, 3.7 vs. 1.1%; p = 0.330, 1.2 vs. 1.1%; p = 1.000, and 1.2 vs. 1.1%; p = 1.000, respectively). CONCLUSION: Prior CS, anterior placenta, and placental lacunae on ultrasound were risk factors for a bleeding-related poor outcome in total PP patients. Total PP patients without these three factors showed the same bleeding-related poor outcome as partial/marginal PP patients.

Volatilization of B4C control rods in Fukushima Daiichi nuclear reactors during meltdown: B-Li isotopic signatures in cesium-rich microparticles.

Boron carbide control rods remain in the fuel debris of the damaged reactors in the Fukushima Daiichi Nuclear Power Plant, potentially preventing re-criticality; however, the state and stability of the control rods remain unknown. Sensitive high-resolution ion microprobe analyses have revealed B-Li isotopic signatures in radioactive Cs-rich microparticles (CsMPs) that formed by volatilization and condensation of Si-oxides during the meltdowns. The CsMPs contain 1518-6733 mg kg-1 of 10+11B and 11.99-1213 mg kg-1 of 7Li. The 11B/10B (4.15-4.21) and 7Li/6Li (213-406) isotopic ratios are greater than natural abundances (~4.05 and ~12.5, respectively), indicating that 10B(n,α)7Li reactions occurred in B4C prior to the meltdowns. The total amount of B released with CsMPs was estimated to be 0.024-62 g, suggesting that essentially all B remains in reactor Units 2 and/or 3 and is enough to prevent re-criticality; however, the heterogeneous distribution of B needs to be considered during decommissioning.