Mirror QCD phase transition as the origin of the nanohertz Stochastic Gravitational-Wave Background.

Several Pulsar Timing Array (PTA) Collaborations have recently provided strong evidence for a nHz Stochastic Gravitational-Wave Background (SGWB). Here we investigate the implications of a first-order phase transition occurring within the early Universe's dark quantum chromodynamics epoch, specifically within the framework of the mirror twin Higgs dark sector model. Our analysis indicates a distinguishable SGWB signal originating from this phase transition, which can explain the measurements obtained by PTAs. Remarkably, a significant portion of the parameter space for the SGWB signal also effectively resolves the existing tensions in both the H0 and S8 measurements in Cosmology. This intriguing correlation suggests a possible common origin of these three phenomena for 0.2<ΔNeff<0.5, where the mirror dark matter component constitutes less than 30% of the total dark matter abundance. Next-generation CMB experiments such as CMB-S4 can test this parameter region.

Postnatal weight gain in very low birth weight infants in Beijing and the risk of retinopathy of prematurity.

AIM: To analyze the low weight gain (WG) from birth to 4 and 6wk of life to predict the development of retinopathy of prematurity (ROP) among very low birth weight (VLBW) preterm babies. METHODS: Three hundred and three newborns with VLBW were analyzed. Body weight measurements were recorded weekly. In all patients, the proportion of the WG was defined as the preterm weight measured at the 4(th) and 6(th) weeks of life minus the birth weight (BW) divided by the BW. Other risk factors for ROP were also analyzed. RESULTS: Mean gestational age and mean BW of the whole cohort were 29.56±1.44wk and 1270.58±176.18g respectively. WG proportion at 4wk postnatal age (18.89%±13.58%) were significantly lower in infants with ROP (P=0.003). WG proportion at 6wk was not different between ROP and no ROP group (42.48%±20.36% vs 46.43%±15.65% P=0.118). When all the other risk factors significant for ROP were included in the logistic regression poor WG did not arise as an independent risk factor. Area under the ROC curve was 0.591 (95%CI: 0.515-0.666; P=0.016). For ROP, the best discriminative cutoff of 18.06% of the proportional WG at the 4(th) week over the BW, sensitivity and specificity values were 67.3% and 50.0% respectively. CONCLUSION: Low WG proportion in the first 4wk of life is maybe an additional predictor of ROP in very low BW infants. Preterm babies with low BW and low WG proportion should be followed closely for ROP.

Dose-dependent protective effect of lithium chloride on retinal ganglion cells is interrelated with an upregulated intraretinal BDNF after optic nerve transection in adult rats.

Neuroprotection of lithium for axotomized retinal ganglion cells (RGCs) is attributed to upregulated intraretinal Bcl-2. As lithium also upregulates brain-derived neurotrophic factor (BDNF) which can rescue axotomized RGCs, it is hypothesized that lithium could protect RGCs through BDNF. This study investigated this hypothesis and a possible relationship between the dose and protection of lithium. All adult experimental rats received daily intraperitoneal injections of lithium chloride (LiCl) at 30, 60 or 85 mg/kg·bw until they were euthanized 2, 7 or 14 days after left intraorbital optic nerve (ON) transection. Our results revealed that RGC densities promoted and declined with increased dose of LiCl and the highest RGC densities were always in the 60 mg/kg·bw LiCl group at both 7 and 14 day points. Similar promotion and decline in the mRNA and protein levels of intraretinal BDNF were also found at the 14 day point, while such BDNF levels increased in the 30 mg/kg·bw LiCl group but peaked in the 60 and 85 mg/kg·bw LiCl groups at the 7 day point. These findings suggested that lithium can delay the death of axotomized RGCs in a dose-dependent manner within a certain period after ON injury and such beneficial effect is interrelated with an upregulated level of intraretinal BDNF.

Birth weight and gestational age on retinopathy of prematurity in discordant twins in China.

AIM: To assess the relative effect of birth weight and gestational age on retinopathy of prematurity (ROP) using preterm twin pairs discordant for birth weigh in a tertiary neonatal intensive care unit in China. METHODS: Fifty-six discordant twin pairs of 112 preterm infants were retrospectively analyzed. The twin pairs were divided into two subgroups based on birth weight in each pair. The occurrence of ROP and severe ROP requiring treatment were compared between the lower birth weight infants and their co-twins with the higher birth weight. Some neonatal morbidities related to prematurity and neonatal characteristics were also compared between the twin pairs. RESULTS: Based on the univariate analysis, gestational age and birth weight were significantly associated with the occurrence and progression of ROP. But no significant differences in ROP between larger and smaller infants were observed in the twin-paired analysis. The incidence of neonatal morbidities regarding respiratory distress syndrome (RDS), patent ductus arteriosus (PDA), intraventricular hemorrhage (IVH), sepsis and neonatal characteristics regarding gender distribution, one- and five-minute Apgar score, postnatal steroid treatment, blood transfusion, supplemental oxygen therapy, and mechanical ventilation were not different between the twins. However, gestational age of ≤28wk was significantly associated with significantly higher rates of ROP and severe ROP. CONCLUSION: Gestational age is a better predictor of ROP than birth weight in the twin-paired study.

Comparison of wavefront aberrations under cycloplegic, scotopic and photopic conditions using WaveScan.

PURPOSE: To evaluate the differences of wavefront aberrations under cycloplegic, scotopic and photopic conditions. METHODS: A total of 174 eyes of 105 patients were measured using the wavefront sensor (WaveScan® 3.62) under different pupil conditions: cycloplegic 8.58 ± 0.54 mm (6.4 mm - 9.5 mm), scotopic 7.53 ± 0.69 mm (5.7 mm - 9.1 mm) and photopic 6.08 ± 1.14 mm (4.1 mm - 8.8 mm). The pupil diameter, standard Zernike coefficients, root mean square of higher-order aberrations and dominant aberrations were compared between cycloplegic and scotopic conditions, and between scotopic and photopic conditions. RESULTS: The pupil diameter was 7.53 ± 0.69 mm under the scotopic condition, which reached the requirement of about 6.5 mm optical zone design in the wavefront-guided surgery and prevented measurement error due to the pupil centroid shift caused by mydriatics. Pharmacological pupil dilation induced increase of standard Zernike coefficients Z(3)(-3), Z(4)(0) and Z(5)(-5). The higher-order aberrations, third-order aberration, fourth-order aberration, fifth-order aberration, sixth-order aberration, and spherical aberration increased statistically significantly, compared to the scotopic condition (P<0.010). When the scotopic condition shifted to the photopic condition, the standard Zernike coefficients Z(4)(0), Z(4)(2), Z(6)(-4), Z(6)(-2), Z(6)(2) decreased and all the higher-order aberrations decreased statistically significantly (P<0.010), demonstrating that accommodative miosis can significantly improve vision under the photopic condition. Under the three conditions, the vertical coma aberration appears the most frequently within the dominant aberrations without significant effect by pupil size variance, and the proportion of spherical aberrations decreased with the decrease of the pupil size. CONCLUSIONS: The wavefront aberrations are significantly different under cycloplegic, scotopic and photopic conditions. Using the wavefront sensor (VISX WaveScan) to measure scotopic wavefront aberrations is feasible for the wavefront-guided refractive surgery.

Analysis of the optical quality by determining the modulation transfer function for anterior corneal surface in myopes.

AIM: To describe the characteristics of modulation transfer function (MTF) of anterior corneal surface, and obtain the the normal reference range of MTF at different spatial frequencies and optical zones of the anterior corneal surface in myopes. METHODS: Four hundred eyes from 200 patients were examined under SIRIUS corneal topography system. Phoenis analysis software was applied to simulate the MTF curves of anterior corneal surface at vertical and horizontal meridians at the 3, 4, 5, 6, 7mm optical zones of cornea. The MTF values at spatial frequencies of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 cycles/degree (c/d) were selected. RESULTS: The MTF curve of anterior corneal surface decreased rapidly from low to intermediate frequency (0-15cpd) at various optical zones of cornea, the value decreased to 0 slowly at higher frequency (>15cpd). With the increase of the optical zones of cornea, MTF curve decreased gradually. 3) In the range of 3 mm- 6 mm optical zones of the cornea, the MTF values measured at horizontal meridian were greater than the corresponding values at horizontal meridian of each spatial frequency, the difference was statistically significant (P<0.05). At 7 mm optical zones of cornea, the MTF values measured at horizontal meridian were less than the corresponding values at vertical meridian at 10-60 spatial frequencies(cpd), and the difference was statistically significant in 25, 30, 35, 40, 45, 50 cpd (P<0.05). CONCLUSION: MTF can be used to describe the imaging quality of optical systems at anterior corneal surface objectively in detail.

Comparison of wavefront aberrations under cycloplegic, scotopic and photopic conditions using WaveScan / Comparação de aberrações de frente de onda sob cicloplegia, condições escotópica e fotópica usando WaveScan

PURPOSE: To evaluate the differences of wavefront aberrations under cycloplegic, scotopic and photopic conditions. METHODS: A total of 174 eyes of 105 patients were measured using the wavefront sensor (WaveScan® 3.62) under different pupil conditions: cycloplegic 8.58 ± 0.54 mm (6.4 mm - 9.5 mm), scotopic 7.53 ± 0.69 mm (5.7 mm - 9.1 mm) and photopic 6.08 ± 1.14 mm (4.1 mm - 8.8 mm). The pupil diameter, standard Zernike coefficients, root mean square of higher-order aberrations and dominant aberrations were compared between cycloplegic and scotopic conditions, and between scotopic and photopic conditions. RESULTS: The pupil diameter was 7.53 ± 0.69 mm under the scotopic condition, which reached the requirement of about 6.5 mm optical zone design in the wavefront-guided surgery and prevented measurement error due to the pupil centroid shift caused by mydriatics. Pharmacological pupil dilation induced increase of standard Zernike coefficients Z3-3, Z4(0) and Z5-5. The higher-order aberrations, third-order aberration, fourth-order aberration, fifth-order aberration, sixth-order aberration, and spherical aberration increased statistically significantly, compared to the scotopic condition (P<0.010). When the scotopic condition shifted to the photopic condition, the standard Zernike coefficients Z4(0), Z4², Z6-4, Z6-2, Z6² decreased and all the higher-order aberrations decreased statistically significantly (P<0.010), demonstrating that accommodative miosis can significantly improve vision under the photopic condition. Under the three conditions, the vertical coma aberration appears the most frequently within the dominant aberrations without significant effect by pupil size variance, and the proportion of spherical aberrations decreased with the decrease of the pupil size. CONCLUSIONS: The wavefront aberrations are significantly different under cycloplegic, scotopic and photopic conditions. Using the wavefront sensor (VISX WaveScan) to measure scotopic wavefront aberrations is feasible for the wavefront-guided refractive surgery.

OBJETIVO: Avaliar as diferenças de aberrações de frente de onda, em diferentes condições pupilares: sob cicloplegia, escotópica e fotópica. MÉTODOS: Um total de 174 olhos de 105 pacientes foram avaliados utilizando o sensor de frente de onda (WaveScan® 3.62) em diferentes condições pupilares: sob cicloplegia 8,58 ± 0,54 mm (6.4 mm-9.5 mm), escotópica 7,53 ± 0,69 mm (5,7 mm - 9,1 mm) e fotópica 6,08 ± 1,14 mm (4,1 mm - 8,8 mm). Diâmetro da pupila, coeficientes de Zernike, RMS ("Root Mean Square") das aberrações de alta ordem e as aberrações dominantes foram comparados entre as condições sob cicloplegia e escotópica, e entre as condições escotópica e fotópica. RESULTADOS: O diâmetro da pupila foi 7,53 ± 0.69 mm sob a condição escotópica e atingiu a exigência de cerca de 6,5 mm de zona óptica na cirurgia baseada em análise de frentes de ondas, evitando erros de medição consequentes à mudança de centroide pupilar provocada por midriáticos. A dilatação farmacológica da pupila induziu aumento dos coeficientes de Zernike Z3-3, Z4(0) e Z5-5. As aberrações de mais alta ordem (terceira, quarta, quinta e sexta ordem) e a aberração esférica aumentaram de forma estatisticamente significativa, em comparação com a condição escotópica (P<0,010). Quando a condição escotópica se mudou para a condição fotópica, os coeficientes de Zernike Z4(0), Z4², Z6-4, Z6-2, Z6² e todas as aberrações de alta ordem diminuíram de forma estatisticamente significativa (P<0,010), demonstrando que a miose acomodativa pode significativamente melhorar a visão sob a condição fotópica. Sob as três condições, a aberração coma vertical apareceu mais frequentemente dentro das aberrações dominantes, sem influência significativa da variação do tamanho da pupila, e a proporção de aberração esférica diminuiu com a diminuição do tamanho da pupila. CONCLUSÕES: As aberrações de frente de onda são significativamente diferentes sob cicloplegia, condições escotópica e fotópica. O uso do sensor de frentes de onda (VISX WaveScan) para medir as aberrações de frente de onda escotópicas é uma opção viável para a cirurgia refrativa baseada em análise de frentes de onda.

[Retinopathy of prematurity screening in 2185 premature infants].

OBJECTIVE: To determine the incidence and risk factors of retinopathy of prematurity (ROP) among premature infants. METHODS: The fundus examination data of 2185 cases of premature infants [birth body weight ≤ 2000 g or gestational age (GA) ≤ 34 weeks] in neonatal intensive care unit of Bayi Children's Hospitals in Beijing between January 2009 and December 2010 were collected and retrospectively analyzed. RESULTS: Of 2185 cases of premature infants (1571 had used supplemental oxygen) received RetCam-II ophthalmoscopy screening, 287 cases developed ROP with the incidence of 13.1% according to the international classification of ROP (ICROP), including 34 cases (11.9%) suffering from zone I, 147 cases (51.2%) from zone II, and 106 cases (36.9%) from zone III. Stage 1, 2 and 3 lesions were 117 cases, 142 cases and 28 cases, accounting for 40.8%, 49.5% and 9.7%, respectively, while stage 4 and stage 5 lesions were not found. Thirty-six cases developed plus disease, accounting for 12.5%. Between ROP and Non-ROP groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (30.6 ± 2.0) g vs (32.4 ± 1.8) W and time of supplemental oxygen [Median 10 d (0 to 71 d) vs 2 d (0 to 36 d)]. Among zone I, II and III groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (29.3 ± 2.2) W vs (30.5 ± 1.9) W vs (31.2 ± 1.8) W and time of supplemental oxygen[Median 14 d (0 to 52 d)vs 10 d (0 to 71 d) vs 8 d (0 to 52 d)] (χ(2) = 257.5, 371.7, 6.695; P < 0.05), while among stage 1, 2 and 3 groups, there were also significant differences in birth weight (1593.3 ± 413.7) g vs (1481.3 ± 336.7) g vs (1325.3 ± 313.7) g, gestational age (30.9 ± 2.0) W vs (30.6 ± 1.9) W vs (29.5 ± 1.7) W and time of supplemental oxygen [Median 8 d (0 to 52 d) vs 11 d (0 to 65 d) vs 12 d (0 to 71 d)] (χ(2) = 230.8, 273.5, 6.695; P < 0.05). In 1004 cases admitted in 2009, 150 developed ROP with the incidence of 14.9%; while in 1181 cases admitted in 2010, 137 developed ROP with the incidence of 11.6%. There was significant differences in the incidence of ROP between these two years (χ(2) = 5.305, P < 0.05). Thirty-eight infants (1.7%) received laser therapy and only 3 infants progressed to stage 4 after laser therapy. Three infants with laser failed stopped progress after vasectomy. Finally, all patients were cured without blindness. CONCLUSIONS: Less birth weight, shorter GA and time of supplemental oxygen are close related to the development of ROP. It is necessary to pay high attention to the screen on premature infants with smaller gestation age, lower birth weight or using oxygen for the reduction or even avoid of blindness.

[The neuroglobin expression when retinal ganglion cells death in acute rats' retina ischemia].

OBJECTIVE: To investigate the intra-retinal expression of neuroglobin (Ngb) and death of retinal ganglion cells (RGCs) in acute retina ischemia rats. METHODS: It was an experimental study. The acute retina ischemia model was established by specific hypothesised left retina artery of Sprague-Dawley rats. Forty rats were divided into four groups (0, 15, 30, 60 min) by the time of retina ischemia. Every group has 10 rats, in one group random 3 rats were detected by Western blotting; 4 rats were detected by ganglion cell counted by hematoxylin and eosin stain and immunohistochemistry fluorescence intensity analysis. The rest 3 rats were detected by Western blotting. The difference among different data were analyzed statistically by One-factor analysis of variance and LSD-t analysis. RESULTS: The intra-retinal expression of Ngb reached maximum after acute ischemia 15 minute (P = 0.000). then the expression began decreasing. After 30 minute acute ischemia, the expression of Ngb had approached normal (P = 0.728), while, the cell number of RGCs began lower than 0 min group (P = 0.011); after 60 minute acute ischemia, the expression of Ngb had been obviously lower than 0 min group (P = 0.001), the cell number of RGCs had been further lower than 0 min group (P = 0.000). The expression of Ngb in RGCs layer was highest in rat retina. The expression in inner plexiform layer and external plexiform layer were lower than the former. The expression of Ngb RGCs was mostly intracytoplasm. After 30 minute acute ischemia, the expression of Ngb were detected in mitochondrial outer compartment and mitochondrial cristae, but in cytoplasm of inner nuclear layer and outer nuclear layer the Ngb was not found. CONCLUSION: Ngb quickly steps-up when RGCs die in acute retina ischemia, and mainly expresses intracytoplasm of RGCs. It has tense relationships with nerve cells' survival in hypoxia.

[Optimization of antibiotics in combination].

OBJECTIVE: To evaluate the antibacterial activity of Ciprofloxacin, Amikacin in combination with beta-lactams against Pseudomonas aeruginosa strains in vitro, to optimize treatment regime for antibiotics on the basis of pharmacokinetics (PK)/pharmacodynamics (PD) and drug sensitivity tests. Methods With checkerboard titration method, the minimal inhibitory concentrations (MIC) of a combination of antibiotics in different concentrations for 33 clinically isolated Pseudomonas aeruginosa strains were determined by broth dilution. Fractional inhibitory concentrations (FIC) were calculated for judging synergic effect of antibiotics. RESULTS: The combination of Amikacin and Ceftazidime showed synergic effects (accounting for 57.6%). The combinations of Ciprofloxacin with Ceftazidime, Cefepime, Imipenem/Cilastatin, Meropenem showed synergic or additive effect. In the study with PK/PD, C(max)/MIC was the principal parameters for evaluation of aminoglycoside and fluoroquinolone antibiotics, while T > MIC was the principal parameter to be used to evaluate beta-lactams antibiotics. CONCLUSION: When antibiotics are used in combination, MICs can be reduced significantly and antibacterial activities are enhanced remarkably. The combination of antibiotics results mainly in synergic or additive effect, and no inhibitory effect is observed. PK/PD analysis plays an important role in planning optimal combination regime to raise clinical efficacy.

Effects of inosine on axonal regeneration of axotomized retinal ganglion cells in adult rats.

Damage to the central nervous system (CNS) is always followed by an irreversible axon degeneration of injured neurons. The purine nucleoside inosine has been shown to induce neurons to regenerate axons in culture and in vivo. In the present study, we investigated the in vivo effects of inosine on the axon regeneration of axotomized retinal ganglion cells (RGCs) in adult rats, using the model of peripheral nerve (PN) grafting onto the ocular stump of the transected optic nerve. Animals were allowed to survive for 4 weeks after surgery with repeated intraperitoneal injections of inosine 1 day before PN grafting till they were killed. Treatment with inosine induced a significant increase (62%) in the number of FluroGold -labeled RGCs regrowing their axons into the PN graft, when compared with the control animals. The axon outgrowth-promoting effect of inosine in adult rodents may represent a potential clinical treatment for injured or degenerated CNS.