Achieving Highly Efficient Photocatalytic Hydrogen Evolution through the Construction of g-C3N4@PdS@Pt Nanocomposites.

Selective supported catalysts have emerged as a promising approach to enhance carrier separation, particularly in the realm of photocatalytic hydrogen production. Herein, a pioneering exploration involves the loading of PdS and Pt catalyst onto g-C3N4 nanosheets to construct g-C3N4@PdS@Pt nanocomposites. The photocatalytic activity of nanocomposites was evaluated under visible light and full spectrum irradiation. The results show that g-C3N4@PdS@Pt nanocomposites exhibit excellent properties. Under visible light irradiation, these nanocomposites exhibit a remarkable production rate of 1289 µmol·g-1·h-1, marking a staggering 60-fold increase compared to g-C3N4@Pt (20.9 µmol·g-1·h-1). Furthermore, when subjected to full spectrum irradiation, the hydrogen production efficiency of g-C3N4@PdS@Pt-3 nanocomposites reaches an impressive 11,438 µmol·g-1·h-1, representing an eightfold enhancement compared to g-C3N4@Pt (1452 µmol·g-1·h-1) under identical conditions. Detailed investigations into the microstructure and optical properties of g-C3N4@PdS catalysts were conducted, shedding light on the mechanisms governing photocatalytic hydrogen production. This study offers valuable insights into the potential of these nanocomposites and their pivotal role in advancing photocatalysis.

Enhancing saltiness perception in bone broth: the additive effect of oil and optimization of sodium-reduction formula for consumer acceptability.

BACKGROUND: Excessive NaCl intake in liquid and semi-solid food (e.g. soup, hot pot base, sauce) poses a high risk to human health, and reducing NaCl intake is a major concern for global health. RESULTS: Using the generalized Labeled Magnitude Scale (gLMS) method, the study verified the possibility of sodium reduction through oil addition. The compromised acceptance threshold (CAT) and hedonic rejection threshold (HRT) were determined. The gLMS results showed that the saltiness intensity of samples containing 0.36% NaCl and 2.29% sunflower seed oil was significantly higher than that of samples containing only 0.36% NaCl (P < 0.05). CAT and HRT results indicated that by adding 3.59% sunflower oil, the NaCl content could be reduced to a minimum of 0.14% without causing sensory rejection in bone broth samples. The quantitative descriptive analysis method was used to determine the effects of NaCl and oil concentrations on the sensory attributes of bone broth samples. Furthermore, it was used to analyze the consumer acceptability drivers in combination with the hedonic scale to optimize the formulation of reduced-salt bone broth products. Notably, sample E (0.36% NaCl, 2.29% fat) not only had a significant salt reduction effect with a 20% decrease in NaCl, but also had improved overall acceptability. CONCLUSION: This study provides theoretical guidance for designing salt-reduction cuisine within the catering and food industries, including bone broth and hot pot bases. © 2024 Society of Chemical Industry.

Cage fusion from bi-cages to tri-cages during nucleation of methane hydrate: a DFT-D simulation.

Water-cage clusters encapsulating guest molecules are the basic components of hydrate crystal structures. Herein, we investigated the fusion process from bi-cages to tri-cages to probe the nucleation mechanism at the initial stage of CH4 hydrate formation by employing dispersion-corrected density functional theory. We found that tri-cages possess high stability by sharing three, rather than two, polygonal faces. In addition, any mono-cage combined with a nonstandard 4151062 cage could achieve considerable stability regardless of which face is shared; this finding illustrates that 4151062 cages are more likely to appear at the early stages of CH4 hydrate nucleation than other nonstandard cages. We then simulated the Raman spectra of CH4 molecules in water-cage to characterize the spectral characteristics of the CH4 hydrate. The C-H symmetric stretching frequency of encapsulated CH4 molecules red-shifted with increasing mono-cage size, which follows the prediction of the "loose cage-tight cage" model. The symmetric stretching vibrational frequencies of trapped CH4 molecules in the tri-cage revealed a clear red-shift compared with those in the component mono- and bi-cages. The cage fusion process and spectroscopic properties described in this work are expected to provide new atomistic insights into CH4 hydrates at the initial nucleation stage.

Feasibility analysis of opto-electronic THz Earth-satellite links in the low- and mid-latitude regions.

Terahertz (THz) communication is considered as a promising technology for the Earth-space application due to its high potential of supporting large data capacity. However, THz wave suffers extreme attenuation from absorption of water vapor (WV) molecules in the propagation path. In this work, we present a theoretical model and analyze the capacities of both inter-satellite and geostationary satellite-to-Earth station (GEO-ES) opto-electronic links operating in the 100-500 GHz band within low- and mid-latitude regions. In our work, THz frequency windows in the 140, 220, 340, and 410 GHz bands with relatively low atmospheric loss are selectively used, targeting a data capacity of 10 Gbps per gigahertz. Our analysis indicates that, in the low-latitude regions, due to high water vapor density (WVD), transmitting and receiving antennas with extremely high gains are required. On the contrary, the mid-latitude regions require less power due to comparatively lower WVD. Moreover, due to seasonal variation in the mid-latitude regions, the requirement of link power budget is tens of decibels less in winter as compared to summer. The results suggest that the establishment of GEO-ES THz links in low- and mid-latitude regions is more realistic in the sub-THz bands, such as 140 and 220 GHz, while the potential of using higher carrier frequencies above 300 GHz for inter-satellite THz links, due to the absence of WV-induced absorption, is supported.

[Effects of Bcl-2 family on the thyroid cell apoptosis of experimental autoimmune thyroiditis mice induced by iodine].

OBJECTIVE: To study the effect of Bcl-2 family members on experimental autoimmune thyroiditis(EAT) and explore the pathogenesis of autoimmune thyroiditis. METHODS: Twenty-four female 4-5 week old NOD-SCID mice were randomly divided into four groups(six mice in each group): control group, high iodine group, poly(I:C) group and high iodine combined with poly(I:C) group. Control group and poly(I:C) group were fed with distilled water, while the high iodine group and high iodine combined with poly(I:C) group were supplied with 0. 05% NaI in their drinking water for 16 weeks. Poly(I:C) group and high iodine combined with poly(I:C) group received intraperitoneal injection of 100 µL poly(I:C)(1 µg/µL) at monday, wednesday and friday of the 11 th and 15 th week. Serum and thyroid were obtained at the last day of the 16 th week. The EAT model was confirmed by ELISA method and pathological HE staining, the apoptosis of thyroid cell were detected by TUNEL method and Cyt-C immunocytochemistry assay, and the mRNA levels of Bcl-2 family members in thyroid were determined by real-time qPCR method. RESULTS: EAT model was established using NOD-SCID mice through high-iodine feeding combined with poly(I:C) intraperitoneal injection. The degree of cell apoptosis and the Cyt-C expression levels were positively correlated with inflammation in thyroid follicular epithelial cells. The mRNA levels of Noxa, PUMA and Bid of high iodine group and high iodine combined with poly(I:C) group were higher than those in control and poly(I:C) groups(P<0. 05). CONCLUSION: Mitochondrial apoptosis pathway is involved in the thyroid cell apoptosis of EAT induced by high iodine, and the apoptosis may be regulated by the up-regulation of Noxa, PUMA and Bid, which belong to the pro-apoptotic members of Bcl-2 family.

Phase Diagram of Methane Hydrates and Discovery of MH-VI Hydrate.

Methane hydrate is not only the predominant natural deposits of permafrost and continental margins of Earth but also the dominant methane-containing phase in the nebula and major moons of gas giants. Depending on the surrounding environment (mainly pressure), seven methane hydrate phases have been discovered by experiment or predicted by computer simulation, such as clathrate methane hydrates I, II, H, and K, and filled-ice methane hydrates III, IV, and V. Using extensive Monte Carlo packing algorithm and density functional theory optimization, here we predict a partial clathrate methane hydrate VI built by basic units of 4262 water bowl encapsulating a methane molecule, which is dynamically stable from the computed phonon dispersion. Its density and structural characteristics are comparable to that of filled-ice methane hydrate III. By calculating the formation enthalpies of a variety of candidate phases at different pressures, a phase diagram of methane hydrates is constructed. As pressure rises, phase transitions occur  among the methane hydrates along with decreasing water/methane molecular ratios. The newly predicted methane hydrate VI emerges as the most stable phase in the region between clathrate phase II and filled-ice phase III, suggesting that methane hydrate VI might be synthesized in a laboratory under accessible conditions.

[Effect of vitamin D deficiency on cardiac autonomic nerve function in obese pre-school children].

OBJECTIVE: To study the effect of vitamin D (VitD) deficiency on cardiac autonomic nerve function in obese pre-school children. METHODS: A total of 242 pre-school children with simple obesity were enrolled, and according to the serum 25-(OH) VitD level, they were divided into VitD deficiency group (76 children), VitD insufficiency group (83 children), and VitD sufficiency group (83 children). The three groups were compared in terms of deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heart rate variability (HRV). The correlations of VitD level with DC, AC, and HRV were analyzed for the VitD insufficiency and VitD deficiency groups. RESULTS: The VitD deficiency group had the lowest DC, root mean square of successive differences between adjacent RR intervals (RMSSD), and low-frequency power (LF) and the highest AC (P<0.05). The VitD insufficiency group had significantly lower DC, RMSSD, and LF and significantly higher AC compared with the VitD sufficiency group (P<0.05). The VitD deficiency group had significantly lower standard deviation of normal-to-normal RR intervals (SDNN) and high-frequency power (HF) than the VitD sufficiency group (P<0.05). In the VitD deficiency group, VitD level was positively correlated with DC, SDNN, standard deviation of average normal-to-normal RR intervals, RMSSD , LF, and HF and was negatively correlated with AC (P<0.05). In the VitD insufficiency group, VitD level was negatively correlated with AC (P<0.05). CONCLUSIONS: Obese pre-school children with VitD insufficiency or deficiency have cardiac autonomic dysfunction, and cardiac vagal tone decreases with the reduction in VitD level.

Phase diagram of water-methane by first-principles thermodynamics: discovery of MH-IV and MH-V hydrates.

Searching novel gas hydrates is an enduring topic of scientific investigations, owing to its outstanding implications on planetology, the origin of life and the exploitation of energy resources. Taking the methane-water system as a representative, we disclose two new dense methane hydrate phases (MH-IV and MH-V) using the Monte-Carlo packing algorithm and density-functional theory (DFT) optimization. Both of these methane clathrates with (CH4)(H2O)4 stoichiometry can be regarded as filled ices, since their hydrogen bond networks are closely related to that of ice i and ice XI, respectively. In particular, the former ice i network is observed for the first time in all gas hydrates. A new chemical composition phase diagram of methane hydrate is constructed. Our newly identified methane hydrate IV emerges in the transition zone for a water-methane ratio between 2 : 1 and 5.75 : 1. It suggests that our MH-IV phase can be stabilized without external pressure, which is superior to previous reported filled ices to apply to energy storage. These findings attest to the importance of composition effects on the packing mechanism of gas hydrate, and provide new perspectives for understanding the physicochemical and geophysical processes in the giant planets of the solar system.

[Cardiac autonomic nerve function in obese school-age children].

OBJECTIVE: To analyze the deceleration capacity (DC) of heart rate, acceleration capacity (AC) of heart rate, and heat rate variability (HRV) in obese school-age children, and to observe the correlations of BMI with DC, AC, and HRV in these children. METHODS: A total of 108 obese school-age children were selected, including 75 cases of ortholiposis and 33 cases of dyslipidemia. A total of 103 healthy school-age children were selected as control group. All the subjects underwent 24-hour ambulatory electrocardiography. The comparisons of DC, AC, and HRV were made between the obese and control groups, as well as between children with ortholiposis and dyslipidemia in the obese group. The correlations of BMI with DC, AC, and HRV were analyzed in the obese group. RESULTS: The obese group showed lower DC, standard deviation of normal-to-normal R-R intervals (SDNN), standard deviation of the average normal-to-normal intervals (SDANN), root mean square of successive differences (RMSSD), low-frequency power (LF), and high-frequency power (HF) than the control group. The AC of the obese group was significantly higher than that of the control group (P<0.05). In the obese group, children with dyslipidemia had significantly lower DC, SDNN, SDANN, RMSSD, LF, and HF, but significantly higher AC and BMI, as compared with those with ortholiposis (P<0.01). In the obese group, BMI was negatively correlated with DC, SDNN, SDANN, RMSSD, and HF (P<0.05), but positively correlated with AC (P<0.05). CONCLUSIONS: Obese school-age children have impaired autonomic nerve function, presenting with reduced vagal tone, which is particularly prominent in those with dyslipidemia. The more obese the children, the lower the vagal tone, which may increase the risks of cardiovascular diseases.

[An analysis of cardiac autonomic nerve function in girls with idiopathic central precocious puberty].

OBJECTIVE: To investigate the cardiac autonomic nerve function in girls with idiopathic central precocious puberty (ICPP). METHODS: A total of 66 girls with ICPP were enrolled, among whom 36 were obese and 30 were not obese. A total of 68 age-matched healthy girls (normal controls) and 51 girls with simple obesity were enrolled as controls. All the subjects underwent 24-hour ambulatory electrocardiography, and deceleration capacity of heart rate (DC), acceleration capacity of heart rate (AC), and heart rate variability (HRV), and body mass index (BMI) were compared between groups. RESULTS: Compared with the normal control group, the ICPP group had significantly lower DC, standard deviation of normal-to-normal R-R intervals (SDNN), standard deviation of the average normal-to-normal intervals (SDANN), root mean square of successive differences (RMSSD), and high-frequency power (HF) and significantly higher AC and BMI. The ICPP group had significantly lower RMSSD and BMI than the simple obesity group (P<0.05). Compared with the ICPP girls without obesity, those with obesity had significantly lower DC, RMSSD, and HF and significantly higher AC and BMI (P<0.05). CONCLUSIONS: Cardiac autonomic dysfunction is seen in girls with ICPP, especially those with obesity, mainly presenting with reduced vagal tone.

Phase diagrams for clathrate hydrates of methane, ethane, and propane from first-principles thermodynamics.

Natural gas hydrates are inclusion compounds composed of major light hydrocarbon gaseous molecules (CH4, C2H6, and C3H8) and a water clathrate framework. Understanding the phase stability and formation conditions of natural gas hydrates is crucial for their future exploitation and applications and requires an accurate description of intermolecular interactions. Previous ab initio calculations on gas hydrates were mainly limited by the cluster models, whereas the phase diagram and equilibrium conditions of hydrate formation were usually investigated using the thermodynamic models or empirical molecular simulations. For the first time, we construct the chemical potential phase diagrams of type II clathrate hydrates encapsulated with methane/ethane/propane guest molecules using first-principles thermodynamics. We find that the partially occupied structures (136H2O·1CH4, 136H2O·16CH4, 136H2O·20CH4, 136H2O·1C2H6, and 136H2O·1C3H8) and fully occupied structures (136H2O·24CH4, 136H2O·8C2H6, and 136H2O·8C3H8) are thermodynamically favorable under given pressure-temperature (p-T) conditions. The theoretically predicted equilibrium pressures for pure CH4, C2H6 and C3H8 hydrates at the phase transition point are consistent with the experimental data. These results provide valuable guidance for establishing the relationship between the accurate description of intermolecular noncovalent interactions and the p-T equilibrium conditions of clathrate hydrates and other molecular crystals.

[Changes in ambulatory electrocardiographic findings after oral administration of low-dose propranolol in infants with hemangioma].

OBJECTIVE: To investigate the effects of oral administration of low-dose propranolol on heart rate variability (HRV), acceleration capacity (AC), deceleration capacity (DC), and cardiac conduction in the treatment of infantile hemangioma. METHODS: A total of 118 infants with hemangioma (≤1 year) were enrolled, and 24-hour ambulatory electrocardiography was performed before oral administration of low-dose propranolol and after one month of administration. The changes in time-domain indices [standard deviation of all normal sinus RR intervals (SDNN), standard deviation of all mean 5-minute RR intervals (SDANN), root mean squared successive difference (RMSSD), and percentage of successive normal sinus RR intervals >50 ms (PNN50)] and frequency-domain indices [low frequency (LF) and high frequency (HF)] for HRV, AC, and DC were observed, as well as abnormalities in cardiac conduction and other aspects after administration of propranolol. RESULTS: After administration of propranolol, the infants had significantly increased SDNN, RMSSD, LF, HF, and PNN50 (P<0.01), and significantly reduced AC, mean heart rate (HR) and minimum HR (P<0.01). The 24-hour ambulatory electrocardiographic findings showed a nonsignificantly higher abnormal rate after administration of propranolol. CONCLUSIONS: In the treatment of infantile hemangioma, propranolol can inhibit the activity of sympathetic nerve and block cardiac conduction, but without any serious adverse effect.

Stability and Vibrations of Guest Molecules in the Type II Clathrate Hydrate: A First-Principles Study of Solid Phase.

Natural gas mixtures are inclusion compounds composed of major light hydrocarbon gaseous molecules (CH4, C2H6, C3H6, and C3H8). Previous ab initio calculations were mainly limited by the cluster models. For the first time, we report first-principles calculations on the stability and vibrational properties of the gas molecules inside the crystalline lattice of type II clathrate. In accordance with our calculations, the larger the size of guest molecule, the more stable the clathrate hydrate for small-sized alkane guest molecules (CnHm, n ≤ 3, m ≤ 8). The interaction energy per guest molecule gradually increases as the number of guest molecules increase for both sII pure and sII mixed hydrates. In addition, the vibrational frequencies of guest molecules trapped in sII hydrate are also simulated. The C-C stretching frequency shows a blue shift as the amount of guest molecules increase. Our theoretical results prove to be valuable insight for identifying the types of guest molecules from experimental spectroscopic data.

Knockdown of WWP1 inhibits growth and induces apoptosis in hepatoma carcinoma cells through the activation of caspase3 and p53.

The activation of oncogenes and the loss of tumor suppressor genes are believed to play critical roles in the pathogenesis of human hepatocellular carcinoma (HCC). The human WW domain containing E3 ubiquitin protein ligase 1 (WWP1) gene is frequently amplified in prostate and breast cancers, however, its role in cancer has not yet been extensively studied. Especially, the role of WWP1 in HCC has not yet been studied. Firstly, we analyzed the expression of WWP1 in HCC samples. We found that protein levels of WWP1 are higher in most HCC cancerous tissues as compared with their matched adjacent non-tumor tissues. Additionally, the WWP1 mRNA was also amplified in all 7 HCC tissues. Knockdown of the endogenous WWP1 using small interfering RNA further showed that deficiency of WWP1 suppressed cell growth and caused apoptosis in HCC cells. Knocking down WWP1 promoted cleaved caspase3 protein and p53 expression in HCC cells, and caspase3 inhibition could prevent cell apoptosis induced by the knockdown of WWP1. All together these results indicate that protein levels of WWP1 in most HCC tissues are higher than non-tumor tissues, and knockdown of WWP1 inhibits growth and induces apoptosis in HCC cells through the activation of caspase3 and p53. Therefore, WWP1 gene might be a potential molecular target of HCC.

Storage capacity and vibration frequencies of guest molecules in CH4 and CO2 hydrates by first-principles calculations.

Using first-principle calculations at B97-D/6-311++G(2d,2p) level, we systematically explore the gas capacity of five standard water cavities (5(12), 4(3)5(6)6(3), 5(12)6(2), 5(12)6(4), and 5(12)6(8)) in clathrate hydrate and study the inclusion complexes to infer general trends in vibrational frequencies of guest molecules as a function of cage size and number of guest molecules. In addition, the Raman spectra of hydrates from CO2/CH4 gases are simulated. From our calculations, the maximum cage occupancy of the five considered cages (5(12), 4(3)5(6)6(3), 5(12)6(2), 5(12)6(4), and 5(12)6(8)) is one, one, two, three, and seven for both CH4 and CO2 guest molecules, respectively. Meanwhile, the optimum cage occupancy are one, one, one, two, and four for CO2 molecules and one, one, two, three, and five for CH4 molecules, respectively. Both the C-H stretching frequency of CH4 and the C-O stretching frequency of CO2 gradually decrease as size of the water cages increases. Meanwhile, the C-H stretching frequency gradually increases as the amount of CH4 molecules in the water cavity (e.g., 5(12)6(8)) increases.

[Research on different expressions of peripheral blood Th1/Th2 cells in psoriasis patients of blood heat syndrome and of blood stasis syndrome].

OBJECTIVE: To explore the correlation between the pathogenesis of psoriasis patients of blood heat syndrome (BHS) and blood stasis syndrome (BSS) and peripheral blood Th1/Th2 cells axis drift, and to observe different expressions of peripheral blood Th1/Th2 cells between healthy subjects and psoriasis patients of BHS and BSS. METHODS: There were 15 patients in the BHS group and 15 in the BSS group. There were 16 patients in the healthy control group. The expressions of CD4+ gamma-interferon (IFN-gamma) and interleukin-4 (IL-4) in the peripheral blood mononuclear cells (PBMCs) were measured by flow cytometry (FACS). The Th1 main cytokines such as IFN-gamma and Th2 cytokines such as IL-4 in the serum of psoriasis patients of different syndromes were detected by enzyme-linked immunosorbent assay (ELISA). The Psoriasis Area and Severity Index score (PASI) were conducted. RESULTS: FACS results showed that the expression level of CD4+ IFN-gamma+ in the PBMCs was significantly higher in the BHS group than in the BSS group and the healthy control group (P < 0.05). Besides, it was positively correlated with the PASI (P < 0.05). ELISA results showed that the peripheral serum level of IFN-gamma was significantly higher in the BHS group than in the BSS group and the healthy control group (P < 0.05). The plasma level of IFN-gamma was positively correlated with the PASI score in the BHS group (P < 0.05). The plasma level of IFN-gamma was negatively correlated with the PASI score in the BSS group (P < 0.05). The peripheral serum level of IL-4 was significantly lower in the BHS group than in the BSS group and the healthy control group (P < 0.05). CONCLUSIONS: Peripheral Th1 cells had dominant state in psoriasis patients of BHS. When psoriasis patients of BHS were transformed to BSS or to the normal level, the expression of peripheral blood Th1 cells decreased.

A new perspective on atrial tachycardia-induced cardiomyopathy: The misdiagnosis of epigastric pain in an 11-year-old girl.

Epigastric pain can be a common clinical manifestation of many diseases, but severe subxiphoid pain caused by tachycardia-induced cardiomyopathy is extremely rare in children. Therefore, the clinical manifestations of the disease are diverse, and improving early detection and treatment of the disease can avoid possible risks. In the case, we report an 11-year-old girl who was initially diagnosed with acute gastritis in a local hospital, but was later diagnosed with atrial tachycardia-induced cardiomyopathy in our hospital after active diagnosis and effective treatment, suggesting early detection and intervention is possible to prevent subsequent serious events.

Combination of electrophysiological mapping, radiofrequency catheter ablation, and atrial appendectomy in a 5-year-old girl with tachycardia-induced cardiomyopathy: a case report.

BACKGROUND: Atrial tachycardia (AT) originating from the left atrial appendage (LAA) is uncommon and the most difficult arrhythmia to eliminate. Therefore, we present the case of a 5-year-old girl with tachycardia-induced cardiomyopathy (TIC) caused by AT originating from the LAA and successfully treated with RFCA associated to left atrial appendectomy. With resolution of AT, we observed a progressive improvement of LV function. The effectiveness and safety of this combination therapy were evaluated over a one-month follow-up period. CASE PRESENTATION: A 5 -year-old female was evaluated for three days of incessant cough and a syncopal episode. Surface echocardiography and 24-hour monitoring showed that the infant had persistent atrial tachycardia. Echocardiography revealed an enlarged tele diastolic diameter (46.1 mm) and malfunctioning (EF 28.53%) left ventricle. The location of the lesion at the apex of the LAA was further confirmed by electrophysiological study and RFCA. After RFCA, the infant's ECG monitor showed that sinus rhythm was maintained for up to 22 h. Subsequently, atrial tachycardia recurred and sinus rhythm disappeared. Finally, atrial appendectomy was performed and sinus rhythm returned to normal. CONCLUSIONS: The heart function of the infant improved and sinus rhythm was maintained, further demonstrating the safety and effectiveness of combined treatment with RFCA and atrial appendectomy after electrophysiological localization of AT from LAA to TIC.

A non-image-forming visual circuit mediates the innate fear of heights in male mice.

The neural basis of fear of heights remains largely unknown. In this study, we investigated the fear response to heights in male mice and observed characteristic aversive behaviors resembling human height vertigo. We identified visual input as a critical factor in mouse reactions to heights, while peripheral vestibular input was found to be nonessential for fear of heights. Unexpectedly, we found that fear of heights in naïve mice does not rely on image-forming visual processing by the primary visual cortex. Instead, a subset of neurons in the ventral lateral geniculate nucleus (vLGN), which connects to the lateral/ventrolateral periaqueductal gray (l/vlPAG), drives the expression of fear associated with heights. Additionally, we observed that a subcortical visual pathway linking the superior colliculus to the lateral posterior thalamic nucleus inhibits the defensive response to height threats. These findings highlight a rapid fear response to height threats through a subcortical visual and defensive pathway from the vLGN to the l/vlPAG.

The retinoblastoma protein selectively represses E2F1 targets via a TAAC DNA element during cellular senescence.

The retinoblastoma (Rb) protein mediates heterochromatin formation at the promoters of E2 transcription factor 1 (E2F1) target genes, such as proliferating cell nuclear antigen and cyclin A2 (CCNA2), and represses these genes during cellular senescence. However, the selectivity of Rb recruitment is still not well understood. Here, we demonstrate that a senescence-associated gene is a direct target of E2F1 and is also repressed by heterochromatin in senescent cells. In contrast, ARF and p27(KIP1), which are also E2F1 targets, are not repressed by Rb and heterochromatin formation. By comparing the promoter sequences of these genes, we found a novel TAAC element that is present in the cellular senescence-inhibited gene, proliferating cell nuclear antigen, and CCNA2 promoters but absent from the ARF and p27(KIP1) promoters. This TAAC element associates with Rb and is required for Rb recruitment. We further determined that TAAC element-mediated Rb association requires the E2F1 binding site, but not E2F1 protein. These results provide a novel molecular mechanism for the different expression patterns of E2F1 targets and afford new mechanistic insight regarding the selectivity of Rb-mediated heterochromatin formation and gene repression during cellular senescence.