A Fish-like Binocular Vision System for Underwater Perception of Robotic Fish.

Biological fish exhibit a remarkably broad-spectrum visual perception capability. Inspired by the eye arrangement of biological fish, we design a fish-like binocular vision system, thereby endowing underwater bionic robots with an exceptionally broad visual perception capacity. Firstly, based on the design principles of binocular visual field overlap and tangency to streamlined shapes, a fish-like vision system is developed for underwater robots, enabling wide-field underwater perception without a waterproof cover. Secondly, addressing the significant distortion and parallax of the vision system, a visual field stitching algorithm is proposed to merge the binocular fields of view and obtain a complete perception image. Thirdly, an orientation alignment method is proposed that draws scales for yaw and pitch angles in the stitched images to provide a reference for the orientation of objects of interest within the field of view. Finally, underwater experiments evaluate the perception capabilities of the fish-like vision system, confirming the effectiveness of the visual field stitching algorithm and the orientation alignment method. The results show that the constructed vision system, when used underwater, achieves a horizontal field of view of 306.56°. The conducted work advances the visual perception capabilities of underwater robots and presents a novel approach to and insight for fish-inspired visual systems.

Design and Analysis of a Novel Bionic Tensegrity Robotic Fish with a Continuum Body.

Biological fish exhibit remarkable adaptability and exceptional swimming performance through their powerful and flexible bodies. Therefore, designing a continuum flexible body is significantly important for the development of a robotic fish. However, it is still challenging to replicate these functions of a biological body due to the limitations of actuation and material. In this paper, based on a tensegrity structure, we propose a bionic design scheme for a continuum robotic fish body with a property of stiffness variation. Its detailed structures and actuation principles are also presented. A mathematical model was established to analyze the bending characteristics of the tensegrity structure, which demonstrates the feasibility of mimicking the fish-like oscillation propulsion. Additionally, the stiffness variation mechanism is also exhibited experimentally to validate the effectiveness of the designed tensegrity fish body. Finally, a novel bionic robotic fish design scheme is proposed, integrating an electronic module-equipped fish head, a tensegrity body, and a flexible tail with a caudal fin. Subsequently, a prototype was developed. Extensive experiments were conducted to explore how control parameters and stiffness variation influence swimming velocity and turning performance. The obtained results reveal that the oscillation amplitude, frequency, and stiffness variation of the tensegrity robotic fish play crucial roles in swimming motions. With the stiffness variation, the developed tensegrity robotic fish achieves a maximum swimming velocity of 295 mm/s (0.84 body length per second, BL/s). Moreover, the bionic tensegrity robotic fish also performs a steering motion with a minimum turning radius of 230 mm (0.68 BL) and an angular velocity of 46.6°/s. The conducted studies will shed light on the novel design of a continuum robotic fish equipped with stiffness variation mechanisms.

Performance Optimization for Bionic Robotic Dolphin with Active Variable Stiffness Control.

Aquatic animals such as fish and cetaceans can actively modulate their body stiffness with muscle to achieve excellent swimming performance under different situations. However, it is still challenging for a robotic swimmer with bionic propulsion mode to dynamically adjust its body stiffness to improve the swimming speed due to the difficulties in designing an effective stiffness adjustment structure. In this paper, based on the special torque mode of a motor, we propose an active variable stiffness control method for a robotic dolphin to pursue better swimming speed. Different from a variable stiffness structure design, a torque control strategy for the caudal motor is employed to imitate the physical property of a torsion spring to act as the variable stiffness component. In addition, we also establish a dynamic model with the Lagrangian method to explore the variable stiffness mechanism. Extensive experiments have validated the dynamic model, and then the relationships between frequency and stiffness on swimming performance are presented. More importantly, through integrating the dynamic model and torque actuation mode-based variable stiffness mechanism, the online performance optimization scheme can be easily realized, providing valuable guidance in coordinating system parameters. Finally, experiments have demonstrated the stiffness adjustment capability of the caudal joint, validating the effectiveness of the proposed control method. The results also reveal that stiffness plays an essential role in swimming motion, and the active stiffness adjustment can significantly contribute to performance improvement in both speed and efficiency. Namely, with the adjustment of stiffness, the maximum speed of our robotic dolphin achieves up to 1.12 body length per second (BL/s) at 2.88 Hz increasing by 0.44 BL/s. Additionally, the efficiency is also improved by 37%. The conducted works will offer some new insights into the stiffness adjustment of robotic swimmers for better swimming performance.

A Survey on Reinforcement Learning Methods in Bionic Underwater Robots.

Bionic robots possess inherent advantages for underwater operations, and research on motion control and intelligent decision making has expanded their application scope. In recent years, the application of reinforcement learning algorithms in the field of bionic underwater robots has gained considerable attention, and continues to grow. In this paper, we present a comprehensive survey of the accomplishments of reinforcement learning algorithms in the field of bionic underwater robots. Firstly, we classify existing reinforcement learning methods and introduce control tasks and decision making tasks based on the composition of bionic underwater robots. We further discuss the advantages and challenges of reinforcement learning for bionic robots in underwater environments. Secondly, we review the establishment of existing reinforcement learning algorithms for bionic underwater robots from different task perspectives. Thirdly, we explore the existing training and deployment solutions of reinforcement learning algorithms for bionic underwater robots, focusing on the challenges posed by complex underwater environments and underactuated bionic robots. Finally, the limitations and future development directions of reinforcement learning in the field of bionic underwater robots are discussed. This survey provides a foundation for exploring reinforcement learning control and decision making methods for bionic underwater robots, and provides insights for future research.

On the Species Delimitation of the Maddenia Group of Prunus (Rosaceae): Evidence From Plastome and Nuclear Sequences and Morphology.

The recognition, identification, and differentiation of closely related plant species present significant and notorious challenges to taxonomists. The Maddenia group of Prunus, which comprises four to seven species, is an example of a group in which species delimitation and phylogenetic reconstruction have been difficult, due to the lack of clear morphological distinctions, limited sampling, and low informativeness of molecular evidence. Thus, the precise number of species in the group and the relationships among them remain unclear. Here, we used genome skimming to generate the DNA sequence data for 22 samples, including 17 Maddenia individuals and five outgroups in Amygdaloideae of Rosaceae, from which we assembled the plastome and 446 single-copy nuclear (SCN) genes for each sample. The phylogenetic relationships of the Maddenia group were then reconstructed using both concatenated and coalescent-based methods. We also identified eight highly variable regions and detected simple sequence repeats (SSRs) and repeat sequences in the Maddenia species plastomes. The phylogenetic analysis based on the complete plastomes strongly supported three main subclades in the Maddenia group of Prunus, while five subclades were recognized based on the nuclear tree. The phylogenetic network analysis detected six hybridization events. Integrating the nuclear and morphological evidence, we proposed to recognize five species within the Maddenia group, i.e., Prunus fujianensis, P. himalayana, P. gongshanensis, P. hypoleuca, and P. hypoxantha. Within this group, the first three species are well-supported, while the gene flow occurring throughout the Maddenia group seems to be especially frequent between P. hypoleuca and P. hypoxantha, eroding the barrier between them. The phylogenetic trees based on eight concatenated hypervariable regions had a similar topology with the complete plastomes, showing their potential as molecular markers and effective barcodes for further phylogeographic studies on Maddenia.

Complete plastome sequence of Prunus hypoxantha (Rosaceae), a species endemic in west of China.

The Chinese endemic species Prunus hypoxantha is of great importance biogeographically, and is distributed in the edge of the Qinghai-Tibetan Plateau. Here, the complete chloroplast genome sequence of P. hypoxantha was assembled based on the Illumina reads. The complete plastome is 158,740 bp in length, with a large single-copy (87,206 bp) region, a small single-copy (18,884 bp) region, and two inverted repeat (26,325 bp) regions. The plastome contains 134 genes. Complete chloroplast genome sequence of P. hypoxantha will provide irreplaceable information in rebuilding the evolutionary history of the Maddenia clade.

Chloroplast genomes elucidate diversity, phylogeny, and taxonomy of Pulsatilla (Ranunculaceae).

Pulsatilla (Ranunculaceae) consists of about 40 species, and many of them have horticultural and/or medicinal value. However, it is difficult to recognize and identify wild Pulsatilla species. Universal molecular markers have been used to identify these species, but insufficient phylogenetic signal was available. Here, we compared the complete chloroplast genomes of seven Pulsatilla species. The chloroplast genomes of Pulsatilla were very similar and their length ranges from 161,501 to 162,669 bp. Eight highly variable regions and potential sources of molecular markers such as simple sequence repeats, large repeat sequences, and single nucleotide polymorphisms were identified, which are valuable for studies of infra- and inter-specific genetic diversity. The SNP number differentiating any two Pulsatilla chloroplast genomes ranged from 112 to 1214, and provided sufficient data for species delimitation. Phylogenetic trees based on different data sets were consistent with one another, with the IR, SSC regions and the barcode combination rbcL + matK + trnH-psbA produced slightly different results. Phylogenetic relationships within Pulsatilla were certainly resolved using the complete cp genome sequences. Overall, this study provides plentiful chloroplast genomic resources, which will be helpful to identify members of this taxonomically challenging group in further investigation.

Inhibition of microRNA-15 protects H9c2 cells against CVB3-induced myocardial injury by targeting NLRX1 to regulate the NLRP3 inflammasome.

BACKGROUND: Viral myocarditis (VMC) is a type of cardiac inflammation that is generally caused by coxsackievirus B3 (CVB3) infection. Several MicroRNAs (miRNAs) are known to play crucial roles in VMC pathogenesis. MiR-15 is reportedly associated with myocardial injury, inflammatory responses and viral infection. Whether miR-15 affects the occurrence and development of VMC remains largely unknown. The roles of miR-15 and their underlying mechanisms in CVB3-stimulated H9c2 cells were assessed in this study. METHODS: We infected H9c2 cells with CVB3 to establish a VMC cellular model. We then determined the effects of miR-15 inhibition on three cardiomyocyte injury markers: lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB) and cardiac troponin-I (cTn-I). The impact on CVB3-induced cell apoptosis and pro-inflammatory cytokines was also investigated. The effects of miR-15 inhibition on NLRP3 inflammasome activation were also assessed. The target relationship between miR-15 and NOD-like receptor X1 (NLRX1) was determined using a luciferase reporter assay. RESULTS: MiR-15 expression was significantly upregulated in H9c2 cells after CVB3 infection. Inhibition of miR-15 significantly decreased the CVB3-induced levels of LDH, CK-MB and cTn-I. It also elevated cell viability, reduced CVB3-induced cell apoptosis and decreased the generation of the interleukins IL-1ß, IL-6 and IL-18. Furthermore, we determined that miR-15 inhibition suppressed NLRP3 inflammasome activation by downregulating NLRP3 and caspase-1 p20 expression. We found a direct target relationship between miR-15 and NLRX1. Additionally, inhibition of NLRX1 reversed the protective effects of miR-15 inhibition against CVB3-induced myocardial cell injury by regulating the NLRP3 inflammasome. CONCLUSION: Our results indicate that miR-15 inhibition alleviates CVB3-induced myocardial inflammation and cell injury. This may be partially due to NLRX1-mediated NLRP3 inflammasome inactivation.

Prospective cohort study of fetal nuchal translucency in first-trimester and pregnancy outcome / 中华妇产科杂志

Objective:To explore the relationship between fetal nuchal translucency (NT) in the first trimester and pregnancy outcome.Methods:A prospective cohort study was conducted in Nanjjing Drum Tower Hospital from December 2015 to December 2018, 4 958 singleton pregnant women were enrolled to screen fetal ultrasound structure and serology in the first trimester, ultrasound in the second trimester and neonatus physical examination 28 days after birth. According to the results of NT, 167 cases of fetus with increased NT (≥3.0 mm) and 4 791 cases of normal NT were divided, moreover, 86 cases with isolate increased NT and 81 cases of increased NT combined with structural abnormality. The prognosis of fetuses with different NT thickness was analyzed, and the pregnancy outcome of fetuses with isolate increased NT or combined with structural abnormality were analyzed. In the first trimester, if the fetal structure was abnormal or the serological screening result was high risk, the chromosomal microarray analysis (CMA) would be performed by chorionic villus sampling to determine the prenatal diagnosis.Results:(1) The pregnancy outcome for fetus of normal NT: there were 4 791 cases with normal NT. Totally, 4 726 cases with normal NT and no structural abnormalities were screened out in the firsttrimester. In this group, 5 cases of aneuploidies were diagnosed based on high risk of maternal serum biomarkers and 83 cases of structural abnormalities were screened out in the subsequent ultrasound scan and the neonatal examination. Another 65 cases with normal NT present complicated with structural anomalies were screened out in the first trimester and 4 cases were diagnosed as aneuploidies. (2) The pregnancy outcome for fetus of isolate increased NT: 66 (76.7%, 66/86) cases of isolated increased NT were performed CMA, 3 cases were diagnosed as trisomy 21 and terminated pregnancy. Another 4 cases were terminated pregnancy privately without cytogenetic diagnosis. No further anomalies were found in 79 cases till 6 to 21 months postnatally. (3) The pregnancy outcome for fetus of increased NT with structural anomalies: increased NT present with structural anomalies were screened out by detailed anomaly scan in the first trimester and 32 of them were confirmed as aneuploidies. In this group, 70 cases terminated pregnancy, 2 cases had spontaneous miscarriages and 9 cases had liveborns (1 newborn was found ventricular septal defect). (4) The pregnancy outcome for fetus of increased NT with or without structural anomalies: the percentage of aneuploidies in fetuses with isolated increased NT (3.5%, 3/86) was significantly lower than those with structural abnormalities (39.5%,32/81). The healthy survival rate in fetuses with isolated increased NT (91.9%,79/86) was significantly higher than those with structural abnormalities (9.9%, 8/81).Conclusions:A detailed first-trimester anomaly scan could improve prenatal screening efficiency of birth defects. Compared to the fetuses with increased NT combined with structural abnormalities, the healthy survival rate of fetuses with isolated increased NT based on detailed first-trimester anomaly scan is higher and the percentage of fetal aneuploidies is lower.

Prospective cohort study of fetal nuchal translucency in first-trimester and pregnancy outcome / 中华妇产科杂志

Objective@#To explore the relationship between fetal nuchal translucency (NT) in the first trimester and pregnancy outcome.@*Methods@#A prospective cohort study was conducted in Nanjjing Drum Tower Hospital from December 2015 to December 2018, 4 958 singleton pregnant women were enrolled to screen fetal ultrasound structure and serology in the first trimester, ultrasound in the second trimester and neonatus physical examination 28 days after birth. According to the results of NT, 167 cases of fetus with increased NT (≥3.0 mm) and 4 791 cases of normal NT were divided, moreover, 86 cases with isolate increased NT and 81 cases of increased NT combined with structural abnormality. The prognosis of fetuses with different NT thickness was analyzed, and the pregnancy outcome of fetuses with isolate increased NT or combined with structural abnormality were analyzed. In the first trimester, if the fetal structure was abnormal or the serological screening result was high risk, the chromosomal microarray analysis (CMA) would be performed by chorionic villus sampling to determine the prenatal diagnosis.@*Results@#(1) The pregnancy outcome for fetus of normal NT: there were 4 791 cases with normal NT. Totally, 4 726 cases with normal NT and no structural abnormalities were screened out in the firsttrimester. In this group, 5 cases of aneuploidies were diagnosed based on high risk of maternal serum biomarkers and 83 cases of structural abnormalities were screened out in the subsequent ultrasound scan and the neonatal examination. Another 65 cases with normal NT present complicated with structural anomalies were screened out in the first trimester and 4 cases were diagnosed as aneuploidies. (2) The pregnancy outcome for fetus of isolate increased NT: 66 (76.7%, 66/86) cases of isolated increased NT were performed CMA, 3 cases were diagnosed as trisomy 21 and terminated pregnancy. Another 4 cases were terminated pregnancy privately without cytogenetic diagnosis. No further anomalies were found in 79 cases till 6 to 21 months postnatally. (3) The pregnancy outcome for fetus of increased NT with structural anomalies: increased NT present with structural anomalies were screened out by detailed anomaly scan in the first trimester and 32 of them were confirmed as aneuploidies. In this group, 70 cases terminated pregnancy, 2 cases had spontaneous miscarriages and 9 cases had liveborns (1 newborn was found ventricular septal defect). (4) The pregnancy outcome for fetus of increased NT with or without structural anomalies: the percentage of aneuploidies in fetuses with isolated increased NT (3.5%, 3/86) was significantly lower than those with structural abnormalities (39.5%,32/81). The healthy survival rate in fetuses with isolated increased NT (91.9%,79/86) was significantly higher than those with structural abnormalities (9.9%, 8/81).@*Conclusions@#A detailed first-trimester anomaly scan could improve prenatal screening efficiency of birth defects. Compared to the fetuses with increased NT combined with structural abnormalities, the healthy survival rate of fetuses with isolated increased NT based on detailed first-trimester anomaly scan is higher and the percentage of fetal aneuploidies is lower.

Ultrathin perpendicular magnetic anisotropy CoFeB free layers for highly efficient, high speed writing in spin-transfer-torque magnetic random access memory.

Perpendicular magnetic anisotropy (PMA) ferromagnetic CoFeB with dual MgO interfaces is an attractive material system for realizing magnetic memory applications that require highly efficient, high speed current-induced magnetic switching. Using this structure, a sub-nanometer CoFeB layer has the potential to simultaneously exhibit efficient, high speed switching in accordance with the conservation of spin angular momentum, and high thermal stability owing to the enhanced interfacial PMA that arises from the two CoFeB-MgO interfaces. However, the difficulty in attaining PMA in ultrathin CoFeB layers has imposed the use of thicker CoFeB layers which are incompatible with high speed requirements. In this work, we succeeded in depositing a functional CoFeB layer as thin as five monolayers between two MgO interfaces using magnetron sputtering. Remarkably, the insertion of Mg within the CoFeB gave rise to an ultrathin CoFeB layer with large anisotropy, high saturation magnetization, and good annealing stability to temperatures upwards of 400 °C. When combined with a low resistance-area product MgO tunnel barrier, ultrathin CoFeB magnetic tunnel junctions (MTJs) demonstrate switching voltages below 500 mV at speeds as fast as 1 ns in 30 nm devices, thus opening a new realm of high speed and highly efficient nonvolatile memory applications.

High-temperature thermal stability driven by magnetization dilution in CoFeB free layers for spin-transfer-torque magnetic random access memory.

Spin-transfer-torque magnetic random access memory (STT-MRAM) is the most promising emerging non-volatile embedded memory. For most applications, a wide range of operating temperatures is required, for example -40 °C to +150 °C for automotive applications. This presents a challenge for STT-MRAM, because the magnetic anisotropy responsible for data retention decreases rapidly with temperature. In order to compensate for the loss of thermal stability at high temperature, the anisotropy of the devices must be increased. This in turn leads to larger write currents at lower temperatures, thus reducing the efficiency of the memory. Despite the importance of high-temperature performance of STT-MRAM for energy efficient design, thorough physical understanding of the key parameters driving its behavior is still lacking. Here we report on CoFeB free layers diluted with state-of-the-art non-magnetic metallic impurities. By varying the impurity material and concentration to modulate the magnetization, we demonstrate that the magnetization is the primary factor driving the temperature dependence of the anisotropy and thermal stability. We use this understanding to develop a simple model allowing for the prediction of thermal stability of STT-MRAM devices from blanket film properties, and find good agreement with direct measurements of patterned devices.

Prenatal ultrasound in diagnosis of fetal unilateral polycystic kidney disease / 中国医学影像技术

Objective To investigate the value of ultrasound in diagnosis of fetal simple unilateral multicystic dysplastic kidney (MCDK) disease.Methods Pregnant women who underwent prenatal ultrasound screening and follow-up were analyzed retrospectively,and 29 fetues with MCDK were found.After exclusion of pregnancy syndrome,other structural abnormalities and chromosomal abnormalities,15 fetues willing to continue pregnancy and accepting the follow-up tracking observation were observed to postpartum.Ipsilateral renal ultrasonographic characteristics,contralateral renal morphology and size,growth and development of children and the renal function were analyzed.Results The minimum follow-up time of the 15 fetus was pregnancy to 7 months after birth,the maximum follow-up time was pregnancy to 5 years of age in children.Ultrasound showed that ipsilateral kidney volume became large in fetal period,reduced gradually in late pregnancy,and atrophy in 5 6 months after birth,even could not displayed with untrasound.The shape,size,and sonographic characteristics of the healthy kidney were similar to the normal gestational age kidney.Prenatal fetal growth indicators and amniotic fluid volume were normal.After birth,except for 1 child with overweight,other children's growth and development indicators were almost normal.Conclusion Fetus with simple unilateral MCDK has a good prognosis.Ultrasound has important value in the examination and follow-up.It can provide reliable basis for prenatal diagnosis and consultation.

First-trimester screening for fetal structural and chromosomal anomalies by detailed early anomaly scan / 中华围产医学杂志

Objectives To assess the performance of first trimester ultrasound screening for fetal structural and chromosomal anomalies based on a detailed anomaly and nuchal translucency (NT) scan at 11-13+6 weeks' gestation.Methods A prospective cohort study was conducted at Nanjing Drum Tower Hospital.Fetuses with a crown-rump length (CRL) between 45 mm and 84 mm scanned during December 2015 to March 2016 were enrolled in this study.After a detailed first-trimester anomaly scan followed the protocol of systematic standardized scan plans,fetuses with congenital abnormalities were screened out.Second trimester ultrasound screening and postnatal examination were performed for further examination of fetal anomalies.Cytogenetic analysis was performed on the fetuses with informed consent.Results (1) A total of 1 154 fetuses were enrolled in this study and among them,36 (3.1％) cases of fetal abnormalities were diagnosed through prenatal examination (35 cases) and postnatal examination (one case).(2) Twenty-one (58.3％) out of the 36 cases with structural and chromosomal anomalies were screened out by using the first-trimester scan,including eight cases of congenital cardiac defect (two cases of atrioventricular septal defect,one case of tricuspid atresia,one case of tetralogy of tetralogy,one case of right ventricle aneurysms and one cases of hypoplastic left heart syndrome combined with cystic hygroma with one case combined with polydactyly),four cases of central nervous system anomaly (three cases of exencephaly and one case of anencephaly combined with double outlet right ventricle),two cases of cleft palate/lip with one case combined with double outlet right ventricle,two cases of exomphalos,one case of amniotic band syndrome,one case of spinal bifida combined with megacystis,one case of umbilical cyst,one case of polydactyly and one case of cystic hygroma.One case of twin pregnancy chose selective fetocide to the fetus with exencephaly and 16 cases terminated pregnancy.The other four cases were confirmed by second trimester ultrasound screening and postnatal examination.Fourteen (38.9％,14/36) new cases of structural and chromosomal anomalies were detected by the second-trimester scan,six of which terminated the pregnancies and the rest were confirmed at term.One (2.8％,1/36) case of polydactyly was detected postnatally.(3) Chromosomal microarray analysis was performed on 28 cases,seven of which were identified as having chromosomal abnormalities including five cases detected in the first trimester and two cases detected in the second trimester.(4) Out of the 20 fetuses with abnormal NT in early trimester,which accounted for 1.7％ of all enrolled fetuses,nine were indentified with major structural or chromosomal abnormalies,a quarter of all abnormal fetus.Conclusions Detailed anomaly scan and NT scan in the first-trimester can increase the detection rate of fetal structural and chromosomal anomalies as compared with the traditional NT scan and provide earlier detection of severe fetal abnormalities as compared with second trimester anomaly scan.

First-trimester ultrasonography in the diagnosis of fetal holoprosencephaly / 中华医学超声杂志（电子版）

Objective To determine the image feature and clinical value of first-trimester ultrasonographic diagnosis of fetal holoprosencephaly.Methods A total 35 580 fetuses at gestational age between 11 + 6 and 13 + 6 weeks were scanned in our hospital by color Doppler ultrasound according to the prenatal ultrasound from Jan 2009 to Jan 2017.Fetal craniocerebral and faceprestige were checked carefully.Cases of fetal holoprosencephaly diagnosed in first-trimester were followed sonographically,and the clinical outcomes were recorded.Results Totally five cases of fetal holoprosencephaly were detected.Four fetuses with other associated malformations were detected by first trimester ultrasound,including one case with beak nosetril,eyes too close,one case with beak nosetril,fetal cleft lip and palate,fetal hydrops,congenital heart disease and mid gut herniation,one case with thickened nucha.One translucency (NT),one case with mandibular micrognathia,one case with trisomy 13 syndrome,the other four cases were not checked.Terminal of pregnancy was performed in four cases during early pregnancy,one case was loss to follow-up.Autopsy was refused in these cases.Fetal appearance revealed one case of cleft lip,single nostril,mandibular micrognathia,one case of hydrops,polyphalangia,microtia,one case of beak nosetril,fetal cleft lip and palate,mid gut herniation,hydrops,one case of beak nosetril,eyes too close.Conclusion Fetal holoprosencephaly can be effectively detected and diagnosed during early pregnancy with standardized prenatal ultrasound.

Clinical value of prenatal ultrasonography in diagnosis of multiple fetal megacystis during early trimester / 中华医学超声杂志（电子版）

Objective To determine the imaging features and clinical value of first-trimester ultrasonographic screening of fetal megacystis in multifetal pregnancy.Methods Retrospective analysis was undertaken in 2159 cases of multifetal pregnancy screened in our hospital at gestational age from 11th to 13 + 6th weeks by color Doppler ultrasound between Jan 2011 and April 2016.Fetal bladder was defined by showing two umbilical arteries and the longitudinal length of the bladder was measured in mid-sagittalplane.Clinical progression of fetal megacystis diagnosed in first-trimester were followed and the outcomes were recorded.Results Totally six cases of fetal megacystis in multifetal pregnancy were detected,in which five cases were detected in one fetus of twin pregnancy and the other case was detected in one fetus of triplet pregnancy.In all cases of fetal megacystis,longitudinal length of the fetal bladder was more than 7 mm and double umbilical arteries were detected.In two cases of naturally-occurring twin pregnancy,abortion was performed and postnatal autopsy revealed prune belly syndrome.In the rest four cases of multifetal pregnancy through in vitro fertilization-embryo transfer (IVF-ET),two cases of twin pregnancies underwent selective feticide.The other two cases of twin and triplet pregnancies refused intervention,among which still birth happened in the megacystis fetus and spontaneous fetal death at gestational age of 13 + 2 weeks happened in the monochorionic monoamniotic twins of the triplet pregnancy.Totally,four live babies were born,among which three were healthy.The other baby was found to have 1.5 Mb deletion in chromosome 17q12 by microarray at gestational age of 32 weeks due to increased renal echogenicity.Conclusions First-trimester ultrasonography can effectively detect and diagnose megacystis in multifetal pregnancy.Early diagnosis and timely intervention are helpful for improving the outcome of fetal megacystis in multifetal pregnancy.

Prenatal diagnosis and follow-up of a case with Lowe syndrome caused by interstitial deletion of Xq25-26 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To report on a sporadic case of Lowe syndrome diagnosed prenatally with ultrasound examination and genetic testing.</p><p><b>METHODS</b>Detailed sonographic fetal screening was performed by an experienced sonographer at 32 weeks of gestation. Fetal cranial magnetic resonance imaging (MRI) was applied to detect potential brain abnormality. Chromosomal microarray analysis (CMA) was conducted on amniotic fluid sample from the fetus and peripheral blood sample from the mother.</p><p><b>RESULTS</b>Congenital cataract and enlarged posterior fossa were detected by fetal ultrasound screening. Fetal cranial MRI found hypoplasia of the gyrus. CMA revealed that the fetus has carried a 633 kb deletion at Xq25-26.1 which encompassed the OCRL gene. The mother was a carrier of the same deletion. Clinical examination after birth confirmed that the neonate was affected with Lowe syndrome in addition with an atrial septal defect.</p><p><b>CONCLUSION</b>Prenatal diagnosis of Lowe syndrome without a family history largely depends on fetal imaging. Should cataract be found by ultrasound screening, fetal MRI may be considered to rule out central nervous system anomalies. CMA assay should also be considered to facilitate the diagnosis.</p>

Effect of Alzheimer's Disease Risk Variant rs3824968 at SORL1 on Regional Gray Matter Volume and Age-Related Interaction in Adult Lifespan.

Sortilin receptor 1 (SORL1) is involved in cellular trafficking of amyloid precursor protein and plays an essential role in amyloid-beta peptide generation in Alzheimer disease (AD). The major A allele in a SORL1 single nucleotide polymorphism (SNP), rs3824968, is associated with an increased AD risk. However, the role of SORL1 rs3824968 in the normal ageing process has rarely been examined in relation to brain structural morphology. This study investigated the association between SORL1 rs3824968 and grey matter (GM) volume in a nondemented Chinese population of 318 adults within a wide age range (21-92 years). Through voxel-based morphometry, we found that participants carrying SORL1 allele A exhibited significantly smaller GM volumes in the right posterior cingulate, left middle occipital, medial frontal, and superior temporal gyri. Considerable interaction between age and SORL1 suggested a detrimental and accelerated ageing effect of allele A on putamen. These findings provide evidence that SORL1 rs3824968 modulates regional GM volume and is associated with brain trajectory during the adult lifespan.

Functional Connectivity Density Mapping of Depressive Symptoms and Loneliness in Non-Demented Elderly Male.

BACKGROUND: Depression and loneliness are prevalent and highly correlated phenomena among the elderly and influence both physical and mental health. Brain functional connectivity changes associated with depressive symptoms and loneliness are not fully understood. METHODS: A cross-sectional functional MRI study was conducted among 85 non-demented male elders. Geriatric depression scale-short form (GDS) and loneliness scale were used to evaluate the severity of depressive symptoms and loneliness, respectively. Whole brain voxel-wise resting-state functional connectivity density (FCD) mapping was performed to delineate short-range FCD (SFCD) and long-range FCD (LFCD). Regional correlations between depressive symptoms or loneliness and SFCD or LFCD were examined using general linear model (GLM), with age incorporated as a covariate and depressive symptoms and loneliness as predictors. RESULTS: Positive correlations between depressive symptoms and LFCD were observed in left rectal gyrus, left superior frontal gyrus, right supraorbital gyrus, and left inferior temporal gyrus. Positive correlations between depressive symptoms and SFCD were observed in left middle frontal gyrus, left superior frontal gyrus, bilateral superior medial frontal gyrus, left inferior temporal gyrus, and left middle occipital region. Positive correlations between SFCD and loneliness were centered over bilateral lingual gyrus. CONCLUSION: Depressive symptoms are associated with FCD changes over frontal and temporal regions, which may involve the cognitive control, affective regulation, and default mode networks. Loneliness is associated with FCD changes in bilateral lingual gyri that are known to be important in social cognition. Depressive symptoms and loneliness may be associated with different brain regions in non-demented elderly male.

Application of chromosome microarray analysis for prenatal diagnosis of a fetus with partial duplication of 1p and uniparental disomy of chromosome 6 / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the genetic cause for a fetus with structural anomaly, and to correlate the phenotype with the genotype.</p><p><b>METHODS</b>Amniotic fluid was obtained following the revelation of structural anomaly by ultrasonography. Cell culture and direct DNA extraction were performed in parallel. G-banded karyotyping analysis and chromosome microarray analysis (CMA) were subsequently carried out.</p><p><b>RESULTS</b>G-banded karyotyping has suggested the fetus to be a normal male. However, CMA analysis has revealed the presence of a mosaic 3.24 Mb duplication of 1p36.33p36.32 (24%) and uniparental disomy (UPD) of chromosome 6. The genetic diagnosis for the fetus was therefore 46,XY, arr 1p36.33 p36.32(849,466-4,090,472)×2-3, (6)×2 hmz. The anomaly can probably explain the ultrasound findings in the fetus.</p><p><b>CONCLUSION</b>Compared with conventional cytogenetic methods, CMA has greater resolution and throughput, and can serve as a more efficient platform for the detection of chromosomal microdeletion, microduplication, loss of heterozygosity and UPD.</p>