Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

[Association study between the KCNE family gene polymorphisms of potassium channel gene and the susceptibility of atrial fibrillation]

Objective: To investigate the relationship between KCNE family gene polymorphisms of potassium channel gene and the susceptibility of atrial fibrillation (AF). Methods: In the case-control study, a total of 648 subjects were studied, of which 338 patients with atrial fibrillation were selected from the Department of Cardiovascular Medicine, Putuo Hospital Affiliated to Shanghai University of Traditional Chinese Medicine from January 2019 to December 2019, and 310 healthy people were selected from the physical examination population during the same period. DNA sequencing technology and polymerase chain reaction (PCR) were used to detect the genotype and allele frequency of rs1805127 of KCNE1, rs9984281 of KCNE2, rs9516, rs626930 of KCNE3 and rs12621643 of KCNE4. Results: The ages of subjects in atrial fibrillation group and control group were (69±13) and (73±8) years, respectively (P=0.077). Men subjects accounted for 57.70% (195 men) and 40.00% (124 men) in the two groups, respectively (P=0.092). The distribution frequencies of the allele C at rs1805127 of gene KCNE1, the allele A at rs9984281 of gene KCNE2 and the allele G at rs12621643 of gene KCNE4 were significantly different between groups (P<0.05). After adjustment for sex, smoking, hypertension, cardiac insufficiency and other factors, it was found that the increase in the frequency of the above three loci would increase the risk of atrial fibrillation (rs1805127 OR=7.064, 95%CI:1.559-31.997; rs9984281 OR=4.210, 95%CI:1.118-15.850; rs12621643 OR=2.679, 95%CI:1.025-6.998). Conclusion: The rs1805127 of KCNE1, the rs9984281 of KCNE2,the rs12621643 of KCNE4 were significantly associated with the susceptibility to atrial fibrillation.

[Interpretation of the International Association of Dental Traumatology guidelines for the management of traumatic dental injuries (2020)]

An update version of the International Association of Dental Traumatology (IADT) guidelines for the management of traumatic dental injuries has been released in June 2020 (http://www.dentaltraumaguide.org). In this current revision, IADT has put forward a "core outcome set" (COS) for the diagnosis and treatment of dental trauma both in children and adults. The COS was developed and underpinned by a systematic review of the outcomes in the literature of dental trauma treatment. An outcome that was relevant to all traumatic dental injuries (TDI) was identified as "generic outcome" and those related only to one or more particular TDI were then included as "injury-specific outcomes". The aims of the present article are to help the dental clinicians in learning the latest version of the guideline so that they may quickly and accurately grasp the essence of the updated content and to assist them to choose the optimized treatment plan after judging and evaluating the specific clinical circumstances so as to maximize the chance of a favorable outcome.

[Occlusal contact of primary dentition at intercuspal position in children with individual normal occlusion]

Objective: To record occlusal contact of primary dentition at maximal intercuspal position in children with individual normal occlusion. Methods: A total of 57 children were recruited from patients of the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology. Inclusion criteria were that the subjects were 3-5 years old with no visually detectable caries or pupal and periapical diseases, had complete primary dentition, had individual normal occlusion, had normal function of craniofacial system, were medically healthy, could cooperate with sampling and had obtained written informed consent from the parents or guardians. Finally, forty-seven children aged 3 to 5 years old were enrolled, including 24 males and 23 females. The age, height and weight of all subjects were (4.1±0.7) years old (ranging 3.0-5.8 years old), (103.7±7.2) cm (ranging 90-120 cm) and (17.1±2.5) kg (ranging 12.5-22.5 kg), respectively. Occlusal abilities such as occlusal contact area, average bite pressure, maximum bite pressure, maximum bite force and occlusal balance were measured with Dental Prescale Ⅱ system. Results: Maximum bite force and occlusal contact area at intercuspal position in children with primary dentition were (567.40±223.84) N (ranging 226.7-1 154.6 N) and (18.56±6.54) mm² (ranging 8.4-41.2 mm²), respectively. There was a significantly strong correlation between maximum bite force and occlusal contact area (r=0.954, P<0.01). Height and weight of children were also positively correlated with their maximum bite force (r=0.397, P=0.022 and r=0.453, P=0.008, respectively). Maximum occlusal bite force and contact occlusal area of boys [(651.80±224.34) N and (20.77±6.97) mm²] were significantly higher and larger than those of girls [(479.34±190.45) N and (16.25±5.27) mm²] (P<0.05). Thirty-two of all 47 children had one occlusal contact point with maximum bite pressure, mostly locating within the primary molar region. Bite forces of anterior and posterior teeth of primary dentition were (124.12±56.99) N and (450.11±205.09) N, respectively, about (21.82±11.40)% and (71.80±21.35)% of maximum bite force of the whole primary dentition. All of the occlusal balance points located in posterior teeth regions. Occlusal contacts were observed at both anterior and posterior teeth of primary dentition with individual normal occlusion. Conclusions: There was a great variation of maximum bite forces of primary dentitions at intercuspal position of children with individual normal occlusion. Maximum bite force of primary dentition was significantly correlated with occlusal contact area, height and weight of children. Occlusal contact points with maximum bite pressure and occlusal bite balance points of primary dentitions mostly located in primary molar regions.

Light Controllable Electronic Phase Transition in Ionic Liquid Gated Monolayer Transition Metal Dichalcogenides

Ionic liquid gating has proved to be effective in inducing emergent quantum phenomena such as superconductivity, ferromagnetism, and topological states. The electrostatic doping at two-dimensional interfaces relies on ionic motion, which thus is operated at sufficiently high temperature. Here, we report the in situ tuning of quantum phases by shining light on an ionic liquid-gated interface at cryogenic temperatures. The light illumination enables flexible switching of the quantum transition in monolayer WS₂ from an insulator to a superconductor. In contrast to the prevailing picture of photoinduced carriers, we find that in the presence of a strong interfacial electric field conducting electrons could escape from the surface confinement by absorbing photons, mimicking the field emission. Such an optical tuning tool in conjunction with ionic liquid gating greatly facilitates continuous modulation of carrier densities and hence electronic phases, which would help to unveil novel quantum phenomena and device functionality in various materials.

[Relationship between insulin resistance, serum VCAM-1, FGF19, IGF-1 and colorectal polyps]

Objective: To explore the relationship between insulin resistance, glucose and lipid metabolism related molecules and colorectal polyps. Methods: A total of 262 healthy people who underwent colonoscopy in Shandong cancer hospital from June 2019 to September 2020 were selected. The levels of serum vascular cell adhesion molecule-1 (VCAM-1), fibroblast growth factor 19 (FGF19), insulin like growth factor (IGF-1), fasting blood glucose and fasting blood insulin were detected by enzyme-linked immunosorbent assay (ELISA). Insulin resistance index (HOMA-IR) was calculated, and the influencing factors of occurrence, pathological type, size and number of polyps were analyzed. Results: Among 262 cases, 116 cases were polyp free, 113 cases were adenomatous polyp and 33 cases were inflammatory polyp. HOMA-IR, VCAM-1 and FGF19 in polyp group were 2.904±1.754, (334.415±139.573) ng/ml and (135.865±98.470) pg/ml, respectively, which were higher than 2.369±1.306, (302.480±99.946) ng/ml and(110.694±76.044) ng/ml in non-polyp group, respectively (P<0.05). Multivariate Logistic regression analysis showed that the gender (OR=4.269, 95%CI: 1.963-9.405) and FGF19 (77.0-131.4 pg/ml: OR=2.385, 95%CI: 1.155-4.926) were independent factors of colorectal polyps. The gender (OR=3.799, 95%CI: 1.650-8.748) and FGF19 (77.0-131.4 pg/ml: OR=2.290, 95%CI: 1.072-4.891) were independent factors of colorectal adenomatous polyps. The gender(OR=6.725, 95%CI: 1.853-24.410) and fasting plasma glucose (≥6.5 mmol/L: OR=0.047, 95%CI: 0.009-0.245) were independent factors of colorectal inflammatory polyps. The gender (OR=3.539, 95% CI: 1.293-9.689) was an independent factor for the occurrence of single polyp. The gender (OR=5.063, 95% CI: 2.048-12.515), FGF19 (77.0-131.4 pg/ml: OR=2.502, 95%CI: 1.102-5.681), fasting plasma glucose (≥6.5 mmol/L: OR=0.282, 95%CI: 0.095-0.839) were independent factors of multiple polyps. The gender (OR=3.416, 95% CI: 1.134-10.289) and fasting insulin (≥9.4 μU/ml: OR=9.480, 95% CI: 1.485-60.521) were independent risk factors for colorectal polyps<0.5 cm. The gender (OR=3.151, 95%CI: 1.244-7.984) and fasting plasma glucose (≥6.5 mmol/L: OR=0.310, 95%CI: 0.102-0.941) were independent risk factors for colorectal polyps with the size of 0.5-0.9 cm. The gender (OR=22.649, 95%CI: 4.154-123.485), age (55 to 64 years old: OR=4.473, 95%CI: 1.070-18.704; ≥65 years old: OR=5.815, 95%CI: 1.300-26.009), BMI (≥28 kg/m(2): OR=5.310, 95%CI: 1.224-23.032) and FGF19 (77.0-131.4 pg/ml: OR=7.474, 95%CI: 1.903-29.351) were independent factors for colorectal polyps with size ≥ 1.0 cm. Gender stratification analysis showed that FGF19 was an independent factor for the occurrence of male polyps (77.0-131.4 pg/ml: OR=6.109, 95%CI: 1.688-22.104) and adenomas (77.0-131.4 pg/ml: OR=6.401, 95%CI: 1.717-23.864). The age (55 to 64 years old: OR=3.783, 95%CI: 1.052-13.611) and VCAM-1 (≥352.8 ng/ml: OR=4.341, 95%CI: 1.142-16.493) were independent risk factors of female polyps. The age (55 to 64 years old: OR=5.743, 95%CI: 1.205-27.362, ≥65 years old: OR=6.885, 95%CI: 1.143-41.467), VCAM-1 (≥352.8 ng/ml: OR=6.313, 95%CI: 1.415-28.159) and IGF-1 (≥7.6 ng/ml: OR=5.621, 95%CI: 1.069-29.543) were independent factors of female adenoma. Conclusions: The occurrences of colorectal polyps and adenomatous polyps are related to insulin resistance and glucose and lipid metabolism. Serum FGF19 is an independent influencing factor for the occurrence of colorectal polyps and adenomatous polyps, and is a potential serological diagnostic marker and therapeutic target for colorectal polyps and adenomatous polyps.

Achromatic and wide-field metalens in the visible region

Optical metalens has been attracting more and more attention in recent years. To date, it is still difficult to simultaneously achieve wide field and broadband imaging in the visible region, which is very important in many applications, such as cameras, microscopy, and other imaging devices. In this paper, we design a double-layer metalens to achieve achromatic imaging over a field of view (FOV) of 60° in the visible light range of 470 nm to 650 nm, and its performance is verified by numerical simulations. The numerical aperture (NA) of the metalens is 0.61 and the average focusing efficiency is > 50% at normal incidence. The metalens has an additional advantage of polarization insensitivity.

A systematic review of olfactory related questionnaires and scales

PURPOSE

Although neglected by science for a long time, the sense of olfaction has received increasing attention from research areas including psychology, neuroscience, clinical medicine and nutrition. With the rise of psychophysical and neuroimaging re- search into olfaction, psychometric tools (e.g. questionnaires and scales) are the basis for the quantitative exploration of inter-in- dividual variability regarding olfactory related responses. The current systematic review is to summarize existing olfaction related questionnaires and/or scales.

METHODS

Peer-reviewed literature on scales and questionnaires related to perception of odors were searched from online databa- ses (PubMed, Web of Science and PsycINFO). Twenty-one articles that meet the following criteria were included in the review: "human species", "physical odor stimuli" and "describing the original development of the tool" and "specific focus on olfaction or odor related responses or behaviors". The psychometric properties, advantages and possible disadvantages were discussed.

RESULTS

Existing psychometric measures focus on various aspects of olfactory related responses and behaviors, including af- fective experiences of odor perception, awareness and attitude towards olfaction, olfactory function and the quality of life change due to olfactory dysfunction, and the ability to create vivid mental odor images. While most of them have been tested to have good reliability and validity, some were relatively time-consuming due to the number of questionnaire items. Besides, although many measures have been used in clinical populations, few have provided information on the predictive validity regarding effecti- veness of clinical intervention on changes of certain responses or behaviors.

SUMMARY

The current review provides an overview of olfactory related questionnaires and scales, highlighting the emotional and affective impact of olfaction and the impact on quality of life due to olfactory dysfunction. With growing interest in olfaction as an important sense, the development and use of psychometrically sound measurements in conjunction with objective assess- ments will advance our understanding of human olfaction and olfactory dysfunction. The review provides a guide for researchers and clinicians alike to select olfactory scales suitable for olfactory research with different experimental purposes and specific samples.

Improving social skills in children with ASD using a long-term, in-home social robot

Social robots can offer tremendous possibilities for autism spectrum disorder (ASD) interventions. To date, most studies with this population have used short, isolated encounters in controlled laboratory settings. Our study focused on a 1-month, home-based intervention for increasing social communication skills of 12 children with ASD between 6 and 12 years old using an autonomous social robot. The children engaged in a triadic interaction with a caregiver and the robot for 30 min every day to complete activities on emotional storytelling, perspective-taking, and sequencing. The robot encouraged engagement, adapted the difficulty of the activities to the child's past performance, and modeled positive social skills. The system maintained engagement over the 1-month deployment, and children showed improvement on joint attention skills with adults when not in the presence of the robot. These results were also consistent with caregiver questionnaires. Caregivers reported less prompting over time and overall increased communication.

[Correlation between Movement Distance of Small Intestinal Contents and Survival Time in Female Rats after Feeding]

OBJECTIVES

To study the correlation between the movement distance of small intestinal contents and survival time in female SD rat models after one-time satiation, and to evaluate its application value for postmortem interval estimation.

METHODS

Adult female SD rats were randomly divided into postprandial groups （1, 2, 3, 4 and 5 h after feeding） and control group. The postprandial groups were fed for 1 h, meanwhile control group was kept fasting. All rats were sacrificed at the given time. The contents in stomach and small intestine were observed, described, compared and photographed, and the movement distance of small intestinal contents was measured. The data of postprandial groups were analysed by one-way analysis of variance.

RESULTS

The stomach and duodenum of control group were empty with a little thin and yellow small intestinal liquid. The gastral cavities of 1 h postprandial group were full of undigested food. The evolutionary changes of character, colour and content were observed in the gastric and small intestinal contents of other postprandial groups. The movement distance of intestinal contents increased while the empty part decreased gradually. The differences among the postprandial groups were statistically significant （P<0.05）.

CONCLUSIONS

After a 24 h fasting with free drinking and the following 1 h feeding, an ideal animal model can be established successfully on female SD rats, which can provide an experimental basis for postmortem interval estimation based on the changes of small intestinal contents in forensic practice.

[A preliminary study of saliva matrix metalloproteinases (MMP-2 and MMP-9) in children with caries]

OBJECTIVE

To investigate the correlation between matrix metalloproteinase (MMP)-2/MMP-9 levels and childhood caries, and the saliva levels of MMP-2/MMP-9 among healthy children and those with different degrees of dental caries, both before and after treatment.

METHODS

In the study, 368 children aged 3 to 5 years were separated into three groups: severe caries group (112 children), mild caries group (98 children) and caries free group (158 children). The children with severe caries were included in treatment group (83 children) after accepting a comprehensive treatment of caries. MMP-2 and MMP-9 levels were determined by enzyme-linked immunosorbent assay (ELISA) and the data were analyzed by the Statistics Package for Social Science (SPSS 13.0). The differences among severe caries group, mild caries group and caries free group were analyzed by SNK-q (Student Newman Keuls). The severe caries group and treatment group were compared by paired t test. The differences between each group were statistically analyzed.

RESULTS

There was no significant difference of the age and gender composition among severe caries group, mild caries group, caries free group and treatment group. The MMP-2 level of severe caries group [(141.3±32.5) μg/L] was higher than those of mild caries group [(107.5±21.3) μg/L] and caries free group [(102.8±18.5) μg/L] (P<0.05). There was no significant difference between mild caries and caries free group (P>0.05). After analysis of 83 children in the treatment group, the level of MMP-2 [(120.1±24.8) μg/L] was lower than before [(144.6±30.3) μg/L] (P<0.05), but was higher than that of caries free group (P<0.05). The MMP-9 levels of severe caries group [(445.8±68.1) μg/L] and mild caries group [(428.6±59.2) μg/L] were higher than that of caries free group [(385.4±60.6) μg/L] (P<0.05), but the difference between severe caries group and mild caries group was not significant (P>0.05). After analysis of 83 children in the treatment group, the alteration of MMP-9 [(432.2±64.7) μg/L] was not significant either (P>0.05).

CONCLUSION

The saliva levels of MMP-2 and MMP-9 in children with severe caries were higher than those in caries free children, even if the treatment was implemented, which suggests that the MMP-2 and MMP-9 in saliva might be related to the caries in children.

[Interleukin-1β and C-reactive protein level in plasma and gingival crevicular fluid in adolescents with diabetes mellitus]

OBJECTIVE

Cytokines produced by various cells are strong local mediators of inflammation. Interleukin-1beta (IL-1β) and C-reactive protein (CRP) play essential roles in the development and progression of diabetes mellitus (DM). Thus periodontal diseases could be related to DM via the same mediators of inflammation. To evaluate plasma and gingival crevicular fluid (GCF) levels of IL-1β and CRP in adolescents with DM to further investigate whether DM has an impact on the levels of inflammation factors at an early stage, and to analyze the risk of developing periodontal diseases in adolescents with DM.

METHODS

A total of 121 adolescents aged from ten to sixteen years were enrolled, 41 adolescents diagnosed with diabetes mellitus were collected in the DM group, and 80 nondiabetic adolescents as the control group. The periodontal indices of each individual were recorded, including plaque index (PLI), modified bleeding index (mBI), probing depth (PD) and attachment loss (AL). GCF and intravenous blood samples were collected, and CRP and IL-1β levels were detected by enzyme-linked immunosorbent assay (ELISA).

RESULTS

(1) PLI of DM group and control group were 1.23±0.05 and 0.95±0.04 separately, with significant difference (P=0.001). DM group and control group had mBI of 0.80±0.08 and 0.51±0.06 separately, with significant difference (P=0.003). Attachment loss was found in none of the subjects. PDs of DM group and control group were (2.37±0.51) mm and (2.31±0.05) mm separately, and there was no significant difference. (2) CRP in GCF was only detectable in partial of the individuals, with a detectable rate of 22.9% (11/48) in total. The detectable rate of CRP in GCF was significantly higher in DM group (38.5%) than that in control group (4.5%, P=0.006). The plasma level of CRP in DM group [0.23 (0.15, 1.89) mg/L] was higher than that in control group [0.19 (0.12, 4.18) mg/L], but without significance (P=0.776). (3) The plasma levels of IL-1β in DM group and control group were (14.11±0.57) ng/L and (14.71±0.50) ng/L separately, but there was no significance (P=0.456). GCF levels of IL-1β in DM group and control group were (12.91±1.95) μg/L and (17.68±3.07) μg/L, without significant difference (P=0.185).

CONCLUSION

Periodontitis was not observed in adolescents with DM at an early stage. However, the rising levels of periodontal indices and CRP in GCF, might indicate that adolescents with DM have a higher risk of developing periodontal diseases in the future.

A novel splicing mutation of ectodysplasin A gene responsible for hypohidrotic ectodermal dysplasia

Hypohidrotic ectodermal dysplasia (HED) is characterized by hypohidrosis, hypodontia, sparse hair, and characteristic facial features. This condition is caused by an ectodysplasin A (EDA) gene mutation. In this study, we examined two HED pedigrees and investigated the molecular genetics of the defect. Direct sequencing analysis revealed a previously unidentified mutation in the EDA splice donor site (c.526 + 1G>A). The function of the mutant EDA gene was predicted through online investigations and subsequently confirmed by splicing analysis in vitro. The mutation resulted in the production of a truncated EDA-A1 protein caused by complete omission of exon 3. This novel functional skipping-splicing EDA mutation was considered to be the cause of HED in the two pedigrees reported here. Our findings, combined with those reported elsewhere, provide an improved understanding of the pathogenic mechanism of HED as well as important information for a genetic diagnosis.

[Age Estimation of Adult Living Donor by Pubic MSCT Three-dimensional Reconstruction]

OBJECTIVES

To establish a method for the age estimation of adult living donor based on pubic MSCT three-dimensional reconstruction and verify its accuracy and reliability.

METHODS

The volume rendering （VR） image data of pubic symphysis surface were collected from 300 volunteers aged over 17 years old. According to different age groups, the age estimation of these volunteers was performed by the method and formula of pubic symphysis surface.

RESULTS

In the 300 volunteers, the difference between biological age and actual age was <1 year in 117 cases, >1-2 years in 178 cases, >2 years in 5 cases.

CONCLUSIONS

MSCT three-dimensional reconstruction technology of pubic symphysis surface can be used to estimate the age of adult living donor, which can provide a high accurate and reliable result.

[Analysis of maternal deaths in Shanghai from 1996 to 2015]

Objective: To analyze the trend of maternal mortality ratio (MMR) and cause of death in Shanghai from 1996 to 2015. Methods: To collect the material about the maternal death and the maternal death audit from 1996 to 2015, and to analyze the MMR, the cause of death and the result of the maternal death audit of Shanghai from 1996 to 2015 retrospectively. Results: (1) The change of MMR: the MMR in Shanghai decreased from 28.84 per 100 000 live births in 1996 to 6.66 per 100 000 live births in 2015. (2) The characteristic of maternal death: the proportion of Shanghai citizens was 27.4%(121/441) and the proportion of migrant women was 72.6%(320/441). The women with advanced maternal age was 8.2% (20/243) since 1996 to 2005, and increased to 16.7% (33/198) since 2006 to 2015. Maternal deaths during pregnancy increased from 27.6%(67/243) in the first 10 years (1996-2005) to 35.4%(70/198) in the recent 10 years (2006-2015) . The intrapartum maternal deaths was 6.2%(15/243) in the first 10 years and in the recent 10 years it was zero. The proportion of postpartum deaths in the first 10 years and in the recent 10 years were 66.3% (161/243) and 64.6%(128/198) respectively. (3) The cause of maternal death: During the recent 10 years, indirect obstetric causes [63.1%(125/198)] was more than direct obstetric causes [36.9% (73/198) ] for the first time. The death causes changed significantly. Postpartum hemorrhage remained the leading cause of maternal deaths, but the specific mortality rate (SMR) of postpartum hemorrhage decreased significantly from 7.42 per 100 000 live births in the first 10 years to 1.51 per 100 000 live births in the recent 10 years. The maternal deaths because of heart disease and cerebrovascular disease rose to the second and the forth reasons. (4) Maternal death audit: the avoidable maternal death ratio decreased from 3.66 per 100 000 live births in the first 10 years to 1.86 per 100 000 live births in the recent 10 years. Conclusions: During the past 20 years, the MMR of Shanghai decreased significantly and was close to the level of developed countries. In recent years, the causes of maternal death become more complicated. With the implementation of the second child policy, women with high risk factors increase, so government investment, policy support should be strengthened to optimize the management.

[Retrospective analysis of pulp revascularization in immature permanent teeth with diffuse pulpitis]

Objective: To evaluate the treatment effectiveness of revascularization in immature permanent teeth with diffuse pulpitis and to provide an alternative approach for the treatment of these teeth. Methods: Clinical and radiographic data were collected from 17 immature permanent teeth which were diagnosed as diffuse pulpitis and with their pulp extirpated at Emergency Department of Peking University School and Hospital of Stomatology. All these teeth were treated using pulp revascularization at Department of Pediatric Dentistry. Clinical success rate was then evaluated based on the clinical and radiographic findings. The increase of root length and dentin wall thickness of the revascularized teeth and the contralateral control teeth were measured and compared according to the preoperative and recall periapical radiographs. Results: The average follow-uptime is (25.8±9.9) months (12-46 months). Totally 13 out of the 17 teeth showed normal clinical and radiographic manifestation and achieved the increasein root length and dentin wall thickness. They met criteria for success treatment. The rest 4 out of the 17 teeth also showed root length and dentin wall thickness increaseand apical foramen closure. However, periapical inflammations were observed during 12 to 36 monthfollow-ups. These cases were recognized as failed. In all the17 teeth, the increase of root length and dentin wall thickness was not significantly different between the revascularized teeth and the contralateral control teeth (P>0.05). Conclusions: Pulp revascularization in young permanent teeth with diffuse pulpitis resulted in similar clinical outcomes in root development and root canal wall formation compared with the contralateral control teeth. However, reinfection might occur during long-term follow-up.