Exploring beam size measurement based on the Talbot effect at BEPCII.

Vertical beam size measurements were carried out at Beijing Electron-Positron Collider II (BEPCII) using a phase grating and an absorption grating based on the Talbot effect. The transverse coherence of synchrotron radiation is closely related to beam size. Due to the partial coherence of the synchrotron radiation source, the coherence length can be calculated by measuring the visibility decay of interferograms recorded at different distances behind the gratings. A vertical beam size of 68.19 ± 2 µm was obtained based on the relationship between the coherence length and beam size at the 3W1 beamline of BEPCII. A comparison of the vertical emittance derived from the grating Talbot method and the synchrotron radiation visible light interferometer method was presented. The vertical emittances from the two methods are 1.41 nm rad and 1.40 nm rad, respectively. The 0.1% difference indicates that the grating Talbot method for beam size measurement is reliable. This technique has great potential for small beam size measurement of fourth-generation synchrotron radiation light sources, considering its small diffraction limitation and simple experimental setups.

A variant of RAG1 gene identified in severe combined immunodeficiency: a case report.

BACKGROUND: The recombination-activating gene 1 (RAG1) protein is essential for the V (variable)-D (diversity)-J (joining) recombination process. Mutations in RAG1 have been reported to be associated with several types of immune disorders. Typical clinical features driven by RAG1 variants include persistent infections, severe lymphopenia, and decreased immunoglobulin levels . CASE PRESENTATION: In this study, a 2-month-24-days-old infant with recurrent fever was admitted to our hospital with multiple infections and absence of T and B lymphocytes. The infant was diagnosed with severe combined immunodeficiency (SCID). A homozygous variation c.2147G>A (NM_000448.2: exonme2: c.2147G>A (p.Arg716Gln)) was identified in the RAG1 gene using whole-exome sequencing and Sanger sequencing. The predicted 3D structure of variant RAG1 indicated altered protein stability. Additionally, decreased expression of variant RAG1 gene was detected at both the mRNA and protein levels. CONCLUSIONS: Our study identified a novel homozygous variant in RAG1 gene that causes SCID. This finding expands the variant spectrum of RAG1 in SCID and provides further evidence for the clinical diagnosis of SCID.

[Risk factors for early acute kidney injury after cardiac arrest in children in the pediatric intensive care unit and a prognostic analysis]. / é‡ç—‡ç›‘æŠ¤å®¤æ‚£å„¿å¿ƒè„åœæåŽæ—©æœŸå‡ºçŽ°æ€¥æ€§è‚¾æŸä¼¤çš„å±é™©å› ç´ åŠé¢„åŽåˆ†æž.

OBJECTIVES: To investigate the risk factors for acute kidney injury (AKI) in children with cardiac arrest (CA) and the influencing factors for prognosis. METHODS: A retrospective analysis was performed on the medical records of the children who developed CA in the pediatric intensive care unit (PICU) of Hunan Children's Hospital from June 2016 to June 2021. According to the presence or absence of AKI within 48 hours after return of spontaneous circulation (ROSC) for CA, the children were divided into two groups: AKI (n=50) and non-AKI (n=113). According to their prognosis on day 7 after ROSC, the AKI group was further divided into a survival group (n=21) and a death group (n=29). The multivariate logistic regression analysis was used to investigate the risk factors for early AKI in the children with CA and the influencing factors for prognosis. RESULTS: The incidence rate of AKI after CA was 30.7% (50/163). The AKI group had a 7-day mortality rate of 58.0% (29/50) and a 28-day mortality rate of 78.0% (39/50), and the non-AKI group had a 7-day mortality rate of 31.9% (36/113) and a 28-day mortality rate of 58.4% (66/113). The multivariate logistic regression analysis showed that long duration of cardiopulmonary resuscitation (OR=1.164, 95%CI: 1.088-1.246, P<0.001), low baseline albumin (OR=0.879, 95%CI: 0.806-0.958, P=0.003), and adrenaline administration before CA (OR=2.791, 95%CI: 1.119-6.961, P=0.028) were closely associated with the development of AKI after CA, and that low baseline pediatric critical illness score (OR=0.761, 95%CI: 0.612-0.945, P=0.014), adrenaline administration before CA (OR=7.018, 95%CI: 1.196-41.188, P=0.031), and mechanical ventilation before CA (OR=7.875, 95%CI: 1.358-45.672, P=0.021) were closely associated with the death of the children with AKI after CA. CONCLUSIONS: Albumin should be closely monitored for children with ROSC after CA, especially for those with long duration of cardiopulmonary resuscitation, low baseline pediatric critical illness score, adrenaline administration before CA, and mechanical ventilation before CA, and such children should be identified and intervened as early as possible to reduce the incidence of AKI and the mortality rate.

[Therapeutic plasma exchange in the pediatric intensive care unit: a single-center retrospective study]. / å„¿ç«¥é‡ç—‡ç›‘æŠ¤å®¤è¡€æµ†ç½®æ¢æ²»ç–—å•ä¸­å¿ƒå›žé¡¾æ€§ç ”ç©¶.

OBJECTIVES: To study the indication for therapeutic plasma exchange (TPE) and related complications in children admitted to the pediatric intensive care unit. METHODS: A retrospective analysis was performed on the medical records of the children who received TPE in the Pediatric Intensive Care Unit, Hunan Children's Hospital, from March 2015 to March 2021. The indication for TPE and related complications were analyzed and compared with the American Society for Apheresis (ASFA) indication categories. RESULTS: A total of 405 TPE treatment sessions were performed for 196 children, among whom 76 children (38.8%) also received continuous renal replacement therapy and 147 children (75.0%) survived. The children with neurological diseases had the highest survival rate of 93.1% (27/29). The top three indications for TPE were hematologic diseases (61/196, 31.1%), sepsis with multiple organ dysfunction (41/196, 20.9%), and liver diseases (36/196, 18.4%). The children with hematologic diseases received the highest number of 129 TPE treatment sessions. The subjects with ASFA category Ⅲ indications accounted for the highest proportion of 76.5% (150/196), followed by those with ASFA category Ⅰ indications (11.2%, 22/196), ASFA category Ⅱ indications (7.1%, 14/196), and unknown category (5.1%, 10/196), and no ASFA category Ⅳ indications were observed. The incidence rate of TPE complications was 12.3% (50/405), and the most common complications were pipeline coagulation (4.2%, 17/405) and hypotension (3.7%, 15/405). No serious adverse events were observed. CONCLUSIONS: TPE can be safely used for the treatment of critically ill children with indications in an experienced pediatric intensive care unit.

Comparison of different modalities of continuous renal replacement therapy with regional sodium citrate anticoagulation in paediatric patients.

BACKGROUND: To evaluate the efficacy and safety of continuous renal replacement therapy (CRRT) modalities with regional sodium citrate anticoagulation (RCA) in children. METHODS: This retrospective study was conducted at the paediatric intensive care unit of Hunan Children's Hospital in China. Medical records of paediatric patients hospitalised for RCA-CRRT between April 2017 and March 2021 were reviewed. Patients received continuous venovenous haemodialysis, continuous venovenous haemofiltration (CVVH), or continuous venovenous haemodiafiltration (CVVHDF). RESULTS: Patients on continuous venovenous haemodialysis (n = 2) were excluded because of their small sample size. The remaining participants were divided into CVVH and CVVHDF groups; 80 patients received CRRT, with 40 and 62 sessions in the CVVH and CVVHDF groups, respectively. The filtre lifespan was longer in the CVVHDF group than in the CVVH group (median value [interquartile range]; 47 [15] hours vs. 35 [17.5] hours; p = 0.029). Compared with the CVVHDF group, the hazard ratio for filtre lifespan in the CVVH group was 3.023 (95% confidence interval 1.820-5.023, p < 0.001). There were no significant differences in ionised calcium levels of the circuits between the two groups at different time points (p < 0.05). Metabolic alkalosis, hyperlactataemia, hypocalcaemia, and hypercalcaemia occurred in both groups, with metabolic alkalosis being the most common complication. No patients in either group experienced sodium citrate accumulation or hypernatraemia. Inter-group differences in the incidence of these complications were not statistically significant (p > 0.05). CONCLUSIONS: Our results suggest that CVVHDF is a better option for RCA-CRRT than CVVH.

[Clinical application of blood purification in treatment of severe adenovirus pneumonia].

OBJECTIVE: To study the role of blood purification in the treatment of severe adenovirus pneumonia. METHODS: A total of 57 children with severe adenovirus pneumonia who underwent mechanical ventilation from February to June, 2019, were enrolled. According to whether blood purification was performed, they were divided into a purification group with 22 children and a conventional group with 35 children. Related clinical indices were collected, including duration of fever, duration of mechanical ventilation, length of stay in the intensive care unit (ICU), and mortality rate. The purification group was analyzed in terms of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) before blood purification and at 48 hours after blood purification, as well as stroke volume variation (SVV), thoracic fluid content (TFC), arterial partial pressure of oxygen/fraction of inhaled oxygen (P/F) value, and partial pressure of carbon dioxide (PCO2) before blood purification and at 6, 12, 24, and 48 hours after blood purification. RESULTS: Compared with the conventional group, the purification group had significantly shorter duration of fever, duration of mechanical ventilation, and length of stay in the ICU (P<0.05), and there was no significant difference in the mortality rate between the two groups (P>0.05). The purification group had significant reductions in IL-6 and TNF-α after blood purification, (P<0.05) and significant reductions in SVV and TFC at 12, 24, and 48 hours after blood purification (P<0.01), as well as a significant increase in P/F value and a significant reduction in PCO2 at 6, 12, 24, and 48 hours after blood purification (P<0.01). CONCLUSIONS: Blood purification as an auxiliary therapy can effectively improve the clinical symptoms of children with severe adenovirus pneumonia, and is thus an option for the treatment of severe adenovirus pneumonia in children.

[Clinical features of severe type 7 adenovirus pneumonia: an analysis of 45 cases].

OBJECTIVE: To study the clinical features of severe type 7 adenovirus pneumonia in children. METHODS: A retrospective analysis was performed for the clinical data of children who were diagnosed with severe type 7 adenovirus pneumonia from February to June, 2019. RESULTS: Among the 45 children, the male/female ratio was 3:2 and the median age was 14 months. All children had repeated fever, cough, and pulmonary moist rales, and the mean duration of fever was 14±4 days. The median time from fever to dyspnea was 8 days, and the time from fever to mechanical ventilation was 11.6±2.5 d. There was no significant increase in white blood cell count, with neutrophils as the main type. There were slight reductions in hemoglobin and albumin, while platelet and fibrinogen remained normal. There were increases in aspartate aminotransferase, lactate dehydrogenase, procalcitonin, and C-reaction protein. The detection rate of mixed pathogens was 84%. Effusion in both lungs was the major change on chest imaging (64%). Bronchoscopic manifestations were endobronchitis, tracheomalacia, and plastic bronchitis. The incidence rate of respiratory complications was 100%, and extrapulmonary complications mainly involved the circulatory system (47%), digestive system (36%), and nervous system (31%). Among the 45 children, 16 were administered with 400 mg/kg intravenous immunoglobulin (IVIG) daily for 5 days, with a mean duration of fever of 16±5 days, and 29 were administered with 1 g/kg IVIG daily for 2 days, with a mean duration of fever of 13±4 days; there was a significant difference in the mean duration of fever between the two groups (P=0.046). The overall mortality rate was 11%. CONCLUSIONS: Severe type 7 adenovirus pneumonia in children has severe conditions, with a high incidence rate of complications and a high mortality rate, so it should be diagnosed and treated as early as possible.