Aripiprazole disrupts cellular synchrony in the suprachiasmatic nucleus and enhances entrainment to environmental light-dark cycles in mice.

Many patients with psychiatric conditions, such as bipolar disorder and major depressive disorder, frequently experience disruptions in their sleep-wake cycles. Several case studies and clinical trials have shown that the administration of aripiprazole, a commonly prescribed antipsychotic drug, alleviates the symptoms of circadian sleep disorders in these patients. This improvement may be attributed to the effects of aripiprazole on the circadian central clock, specifically the hypothalamic suprachiasmatic nucleus (SCN), which regulates various circadian physiological rhythms, including the sleep-wake cycle, in mammals. To examine whether aripiprazole facilitates adaptation to changes in the light-dark cycle, we orally administered aripiprazole to mice and subjected them to jet-lag experiments. Mice receiving aripiprazole were more rapidly entrained to 6 h advanced light-dark cycles. Moreover, we examined the effect of aripiprazole on the cellular rhythms of SCN slice cultures and found that aripiprazole disrupted cellular synchronization in the SCN, thereby accelerating the damping of the SCN rhythm at the population level. Adenosine 3'5' monophosphate (cAMP) assay using a bioluminescence indicator revealed that intracellular cAMP level in the SCN increased following aripiprazole treatment. However, this increase was blocked by pre-treatment with the serotonin 1A receptor (5-HT1AR) antagonist. Based on these findings, we propose that aripiprazole modulates intracellular signaling, including 5-HT1AR-mediated cAMP signaling, and desynchronizes SCN neurons, ultimately leading to enhanced entrainment to phase advanced light-dark cycles in mice. These findings indicate that the improvement in sleep symptoms reported in patients with psychiatric disorders receiving aripiprazole may be due to modulation of the circadian clock. Our study provides novel insights into the potential clinical applications of aripiprazole in patients with various circadian sleep disorders.

Incorporating structural plasticity into self-organization recurrent networks for sequence learning.

Introduction: Spiking neural networks (SNNs), inspired by biological neural networks, have received a surge of interest due to its temporal encoding. Biological neural networks are driven by multiple plasticities, including spike timing-dependent plasticity (STDP), structural plasticity, and homeostatic plasticity, making network connection patterns and weights to change continuously during the lifecycle. However, it is unclear how these plasticities interact to shape neural networks and affect neural signal processing. Method: Here, we propose a reward-modulated self-organization recurrent network with structural plasticity (RSRN-SP) to investigate this issue. Specifically, RSRN-SP uses spikes to encode information, and incorporate multiple plasticities including reward-modulated spike timing-dependent plasticity (R-STDP), homeostatic plasticity, and structural plasticity. On the one hand, combined with homeostatic plasticity, R-STDP is presented to guide the updating of synaptic weights. On the other hand, structural plasticity is utilized to simulate the growth and pruning of synaptic connections. Results and discussion: Extensive experiments for sequential learning tasks are conducted to demonstrate the representational ability of the RSRN-SP, including counting task, motion prediction, and motion generation. Furthermore, the simulations also indicate that the characteristics arose from the RSRN-SP are consistent with biological observations.

Characteristics and risk factors for spontaneous and postoperative consecutive exotropia in children with esotropia.

Background: To investigate the risk factors for the development of consecutive exotropia (CXT) by comparing patients with spontaneous or postoperative CXT during follow-up with another group of patients who had no deviation or less than 10 prism dioptre (PD) esotropia. Methods: In this retrospective cohort study, 6 patients with spontaneous CXT (group A), 13 patients with postoperative CXT (group B), and 39 patients with no exotropia (group C) were enrolled. Probable risk factors for CXT were evaluated among the groups. Kruskal-Wallis H test was used to determine if any significant differences were present among the groups. Fisher's exact test or Mann-Whitney U test was used for univariate analyses to compare differences between case groups or between case and control groups. The Bonferroni method was used to conduct multiple comparisons. Results: The follow-up period of spontaneous CXT patients was significantly longer than that of postoperative CXT and nonconsecutive exotropia patients (p = 0.035 and p < 0.001, respectively). The interval between alignment and CXT onset in spontaneous CXT patients was slightly longer than that in postoperative CXT patients, but not significantly difference (6.50 vs. 5.00 years, p = 0.072). Vertical deviation was associated with a high risk of postoperative CXT (p = 0.001). Most [38 (97.44%)] nonconsecutive exotropia patients had fusion; conversely, the absence of fusion function (p < 0.001) as well as stereoacuity (p = 0.029) were associated with a high risk of CXT. Conclusion: Vertical deviation and poor binocular function are strongly associated with a high risk of CXT. Children with spontaneous CXT are highly recommended to be followed-up long-term, while they maintain long-term ocular alignment before developing consecutive exotropia from comitant esotropia (CE).

Diagnostic Capability of Isolated-Check Visual Evoked Potential for Early to Moderate Primary Open-Angle Glaucoma.

This study aimed to evaluate the diagnostic capability of isolated-check visual evoked potential (icVEP) for primary open-angle glaucoma (POAG) via comparison with visual field (VF) tests and pattern visual evoked potential (PVEP). This cross-sectional study enrolled 68 subjects, including 33 POAG patients and 35 controls. All subjects underwent a complete ophthalmic examination, including icVEP, PVEP, and VF tests. The diagnostic performance, the area under the receiver operating characteristic curve (AUC), the integrated discrimination index (IDI), and the net reclassification index (NRI) were calculated. The clinical benefits of the three tests were compared via decision curve analysis (DCA) of the signal-to-noise ratio (SNR) from icVEP, the P100 latency and amplitude of 1° and 0.25° checks from the PVEP, pattern standard deviation (PSD), and mean deviation (MD) from the VF test. The SNR, MD and PSD, PVEP P100 latency of 0.25° checks, and P100 amplitude (both 1° and 0.25° checks) showed significant differences between the POAG and control groups (* p < 0.05), except for the P100 latency of 1° checks. Regarding diagnostic ability, the three tests, AUC, IDI, and NRI, showed no significant difference (p > 0.05). The DCA showed that the clinical benefits of icVEP (SNR) were comparable to those of VF (MD and PSD) and better than those of PVEP (P100 latency and amplitude). In addition, no significant difference was found in the consistency analysis of the qualitative comparison between the icVEP, VF, and PVEP (McNemar p > 0.05). In this study, icVEP showed a diagnostic ability for early to moderate POAG patients comparable to VF and PVEP. IcVEP might be applied as a supplementary psychophysical examination method in addition to VF examinations for special POAG populations who have difficulty cooperating with the VF examination.

Choroidal thickness and vascular microstructure parameters in Chinese school-age children with high hyperopia using optical coherence tomography.

Background: The current study was to evaluate the choroidal thickness (CT) and vascular microstructure parameters in Chinese children with high hyperopia through enhanced depth imaging optical coherence tomography (EDI-OCT). Methods: Cross-sectional study. A total of 23 children with high hyperopia and 29 children with normal refractive status were retrospectively enrolled in the study. The measurement of the macular CT, 7 points: the sub-foveal area point, the temporal and nasal points at a radius of 0.5-mm, 1.5-mm, and 3-mm were measured. After binarization of the OCT images, the total choroidal area (TCA), stromal area (SA) as well as the luminal area (LA) were identified and measured. The choroidal vascularity index (CVI) was defined as the ratio of LA to TCA. The independent t-test for normal distributions and Kruskal-Wallis tests for non-normal distributions were used to compare other parameters between groups. The Tamhane's T2 test was performed to adjust for multiple comparisons between groups within each analysis. Results: The subfoveal CT (SFCT) in the high hypermetropic group was significantly thicker than that in normal controls (309.22 ± 53.14 µm vs. 291.27 ± 38.27 µm; P = 0.019). At 0.5 mm, 1.5 mm, and 3.0 mm in diameter, the nasal choroidal sectors of the high hyperopia eyes were significantly thicker than that of the control (P < 0.05). There was significant difference in the choroidal vascular parameters. TCA and LA in the high hyperopia eyes was significantly larger than that of the normal control eyes (3078129.54 ± 448271.18 µm2 vs. 2765218.17 ± 317827.19 µm2, 1926819.54 ± 229817.56 µm2 vs. 1748817.18 ± 191827.98 µm2; P = 0.009, P = 0.011; Table 2). SA values were 1086287.55 ± 212712.11 um2 in the high hyperopia eyes and 999712.71 ± 209838.12 µm2 in the control eyes. The CVI and LA/SA ratio values were differed significantly in the two groups (P = 0.019, P = 0.030, respectively). AL was significantly correlated with SFCT (r = -0.325, P = 0.047), but not significantly correlated with other parameters. Spherical equivalent (SE) was significantly correlated with AL and SFCT (r = -0.711, r = 0.311; P = 0.001, P = 0.016), whereas no significant association between sphere and other parameters. Conclusion: The choroidal structure of the high hyperopia eyes was different from the normal control eyes. The thicker SFCT, higher LA, and TCA were characteristic of high hyperopia eyes. Choroidal blood flow may be decreased in amblyopic eyes. SFCT of high hyperopia children abnormally increased and correlated with shorter AL and higher SE. AL and SE affect choroidal structure and vascular density.

Selective transplantation method of leafy vegetable seedlings based on ResNet 18 network.

To solve the problem of low survival rate caused by unscreened transplanting of seedlings. This study proposed a selective transplanting method of leafy vegetable seedlings based on the ResNet 18 network. Lettuce seedlings were selected as the research object, and a total of 3,388 images were obtained in the dataset. The images were randomly divided into the training set, validation set, and test set in the ratio of 6:2:2. The ResNet 18 network was used to perform transfer learning after tuning, identifying, and classifying leafy vegetable seedlings, and then establishing a model to screen leafy vegetable seedlings. The results showed that the optimal detection accuracy of the presence and health of seedlings in the training data set was above 100%, and the model loss remained at around 0.005. Nine hundred seedlings were selected for the validation test, and the screening accuracy rate was 97.44%, the precision rate of healthy seedlings was 97.56%, the recall rate was 97.34%, the precision rate of unhealthy seedlings was 92%, and the recall rate was 92.62%, which was better than the screening model based on the physical characteristics of seedlings. If they were identified as unhealthy seedlings, the manipulator would remove them during the transplanting process and perform the seedling replenishment operation to increase the survival rate of the transplanted seedlings. Moreover, the seedling image is extracted by background removal technology, so the model processing time for a single image is only 0.0129 s. This research will provide technical support for the selective transplantation of leafy vegetable seedlings.

Goniosynechialysis combined with multiple surgeries for secondary glaucoma in nanophthalmos: A case report.

BACKGROUND: Management of secondary glaucoma in nanophthalmos has always been challenging, especially for patients with extremely short axial length and extensive angle synechia. This case report discusses a nanophthalmic patient with secondary glaucoma and extensive angle synechia. CASE PRESENTATION: A 60-year-old woman was referred to our hospital with uncontrolled intraocular pressure (IOP) in her left eye (LE). Slitlamp examination revealed small cornea and shallow anterior chamber (AC) in both eyes. Extensive angle synechia was seen on gonioscopy, and the IOP and axial length were 36 mmHg/15.79 mm in the left eye. She was diagnosed with nanophthalmos and secondary angle-closure glaucoma LE. Laser peripheral iridectomy (LPI) was performed, but the IOP LE remained elevated and uncontrolled on brinzolamide and brimonidine. The IOP LE was then normalized with the application of 2% pilocarpine. During the follow-up period, the AC of the LE showed progressive shallowing, and 5 months post LPI the IOP became uncontrollable. Goniosynechialysis combined with phacoemulsification, lamellar sclerectomy, sclerostomy, peripheral iridectomy, capsulotomy, and anterior vitrectomy were performed LE. Immediately after surgery, the AC deepened and the IOP stabilized. However, the IOP rose again post-surgically at 1 week and again at 2 months. A generally shallow AC and obstructed capsule hole were present. YAG laser capsulotomy was performed, and the IOP normalized and the AC deepened. Eighteen months after surgery, the IOP LE was 12 mmHg and the AC remained stable. CONCLUSION: Goniosynechialysis combined with multiple surgical procedures could be considered an alternative treatment regimen for nanophthalmos patients with secondary glaucoma and extensive angle synechia.

ß-Trioxopyrrocorphins: pyrrocorphins of graded aromaticity.

Octaethyltrioxopyrrocorphins unexpectedly show macrocycle-aromatic properties, even though they contain the macrocyclic π-system of the non-aromatic pyrrocorphins (hexahydroporphyrins). Two of the four possible triketone regioisomers were first reported in 1969 by one-pot oxidation of octaethylporphyrin but remained essentially unexplored since. We detail here the targeted preparation of the remaining two triketone isomers and the optical and NMR spectroscopic properties of all isomers. All four regioisomers possess unique electronic properties, including broadly varying degrees of diatropicity that were experimentally determined using 1H NMR spectroscopy and computationally verified. Structural patterns modulating the aromaticity were recognized. These differences highlight the regioisomerically differentiated influences of the three ß-oxo-functionalities. We also present the solid state structure of the two most common isomers (in their free base form or as zinc complexes), allowing further conclusions to be made about the resonance structures present in these triketones. Remarkably, also, the halochromic properties of the triketones differ sharply from those of regular (hydro)porphyrins, providing further support for the proposed 16-membered, 18 π-electron aromatic ring-current. The work conceptually expands the understanding of tris-modified hydroporphyrinoid analogues and the factors that enable and control porphyrinoid aromaticity.

Structural and Photophysical Characterization of All Five Constitutional Isomers of the Octaethyl-ß,ß'-dioxo-bacterio- and -isobacteriochlorin Series.

It is well-known that treatment of ß-octaethylporphyrin with H2 O2 /conc. H2 SO4 converts it to a ß-oxochlorin as well as all five constitutional isomers of the corresponding ß,ß'-dioxo-derivatives: two bacteriochlorin-type isomers (ß-oxo groups at opposite pyrrolic building blocks) and three isobacteriochlorin-type isomers (ß-oxo-groups at adjacent pyrrolic building blocks). By virtue of the presence of the strongly electronically coupled ß-oxo auxochromes, none of the chromophores are archetypical chlorins, bacteriochlorins, or isobacteriochlorins. Here the authors present, inter alia, the single crystal X-ray structures of all free-base diketone isomers and a comparative description of their UV-vis absorption spectra in neutral and acidic solutions, and fluorescence emission and singlet oxygen photosensitization properties, Magnetic Circular Dichroism (MCD) spectra, and singlet excited state lifetimes. DFT computations uncover underlying tautomeric equilibria and electronic interactions controlling their electronic properties, adding to the understanding of porphyrinoids carrying ß-oxo functionalities. This comparative study lays the basis for their further study and utilization.

Applications of the isolated-check visual evoked potential in primary open angle glaucoma with or without high myopia.

AIM: To explore the diagnostic performance of isolated-check visual evoked potential (icVEP) for primary open angle glaucoma (POAG) in both highly myopic and non-highly myopic populations and compare it with those of optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT) parameters. METHODS: A total of 126 participants were recruited, including 31 highly myopic participants with POAG (HM-POAG), 36 non-highly myopic participants with POAG (NHM-POAG), 25 highly myopic participants without POAG (HM) and 34 controls without high myopia (Normal). All the participants underwent a complete ophthalmic examination. The signal-to-noise ratio (SNR) was used to assess the icVEP. Both qualitative and quantitative diagnostic performances of OCT, HRT and the icVEP were analyzed and compared. RESULTS: Based on the criterion of SNR≤1, the diagnostic performance of the icVEP in highly myopic subjects [area under the receiver operating characteristic curve (AUC)=0.862] was better than that in non-highly myopic subjects (AUC=0.789), and the SNR had fairly good specificity. In distinguishing the HM-POAG and HM groups, the AUC of the SNR was not different from those of the OCT and HRT parameters (P>0.05) in either the qualitative or quantitative comparison. In the qualitative analysis, the icVEP showed good consistency with damage to the central 10° of the visual field (kappa=0.695-0.747, P<0.001). CONCLUSION: The icVEP has the potential to discriminate individuals with and without POAG, especially in populations with high myopia.

Comparison of corneal biomechanics among primary open-angle glaucoma with normal tension or hypertension and controls.

BACKGROUND: Normal tension glaucoma (NTG) is a less pressure-dependent type of glaucoma with characteristic optic neuropathy. Recently, the biomechanical mechanism has been thought to account for glaucomatous optic neuropathy to some degree. We intended to compare dynamic corneal response parameters (DCRs) among patients with primary open-angle glaucoma with normal tension or hypertension and controls. The correlations between DCRs and known risk factors for glaucoma were also analyzed. METHODS: In this cross-sectional study, 49 NTG subjects, 45 hypertension glaucoma (HTG) subjects, and 50 control subjects were enrolled. We compared the differences in DCRs using corneal visualization Scheimpflug technology among the NTG, HTG, and control groups. We also analyzed the correlations between DCRs and known risk factors for glaucoma (eg, central corneal thickness [CCT], intraocular pressure [IOP], etc). RESULTS: The maximum inverse concave radius (NTG: 0.18 [0.17, 0.20] mm-1; control: 0.17 [0.16, 0.18] mm-1; P = 0.033), deformation amplitude ratio of 2 mm (DAR 2 mm, NTG: 4.87 [4.33, 5.39]; control: 4.37 [4.07, 4.88]; P < 0.001), and DAR 1 mm (NTG: 1.62 [1.58, 1.65]; control: 1.58 [1.54, 1.61]; P < 0.001) were significantly higher in NTG than in the controls. The integrated radius (IR, NTG: 8.40 ±â€Š1.07 mm-1; HTG: 7.64 ±â€Š1.31 mm-1; P = 0.026) and DAR 2 mm (NTG: 4.87 [4.33, 5.39]; HTG: 4.44 [4.12, 5.02]; P < 0.007) were significantly higher, whereas the stiffness parameter at the first applanation (SP-A1, NTG: 91.23 [77.45, 107.45]; HTG: 102.36 [85.77, 125.12]; P = 0.007) was lower in NTG than in HTG. There were no significant differences in the DCRs between HTG and control groups (P > 0.05). In the univariate and multivariate analyses, some of the DCRs, such as IR, were negatively correlated with CCT and IOP, whereas SP-A1 was positively correlated with CCT and IOP. CONCLUSIONS: The cornea was more deformable in NTG than in HTG or controls. There were no significant differences in corneal deformability between HTG and controls. The cornea was more deformable with the thinner cornea and lower IOP.

Diagnostic capability of different morphological parameters for primary open-angle glaucoma in the Chinese population.

BACKGROUND: To assess the diagnostic capability of novel Bruch's membrane opening (BMO)-based disc parameters, the BMO-minimum rim width (BMO-MRW) and the BMO-minimum rim area (BMO-MRA) in the Chinese population and compare them to the retinal nerve fiber layer (RNFL) from optical coherence tomography (OCT) and the rim area (RA) from the Heidelberg retinal tomograph-III (HRT-III). METHODS: In total, 200 eyes of 77 healthy and 123 primary open-angle glaucoma (POAG) subjects were included in this cross-sectional study. All participants underwent the visual field test and structural measurements by OCT and HRT-III. The areas under the receiver operating characteristic curves (AUCs) of different structural parameters were calculated to assess their diagnostic power and compared using the DeLong test. RESULTS: In populations with different characteristics, the BMO-MRW and BMO-MRA had better diagnostic power than the RA. In discriminating between all POAG subjects and healthy controls and between early-stage patients and controls, the global BMO-MRW had comparable AUCs with the RNFL, but the BMO-MRA had lower AUCs than the RNFL. In healthy subjects with macrodiscs, both the global and sectoral BMO-MRW were thinner than those in healthy subjects with normal disc size. The AUCs of BMO-MRA, BMO-MRW and RNFL in subjects with macrodiscs were comparable. Additionally, in the myopic population, the BMO-MRA and BMO-MRW had comparable AUCs with the RNFL. CONCLUSIONS: The BMO-MRW had comparable diagnostic power with the RNFL, and compared with BMO-MRW, the BMO-MRA might have advantages in certain populations, such as macrodiscs. All OCT-derived parameters exceeded the RA in diagnostic capability.

Structural characterization, hypoglycemic effects and antidiabetic mechanism of a novel polysaccharides from Polygonatum kingianum Coll. et Hemsl.

The rhizome of Polygonatum kingianum has been used as a traditional medicine in China. In this study, a novel polysaccharides (PKPs-1) was isolated from P. kingianum and characterized by its molecular weight, primary structure. The hypoglycemic activity of PKPs-1was investigated by in vitro assay with the HepG2 cell line and in vivo test using STZ-induced diabetic mice. Results showed that the average molecular weight of PKPs-1 was 14.05 kDa and is composed mainly of glucose and mannose. Methylation analysis indicated that this polysaccharides fraction consisted mainly of ß1,2-link glucose. Besides, PKPs-1 exhibited significant anti-hyperglycemic activity on STZ-induced mice, improved insulin tolerance, and affected the metabolism of serum lipids. Results of real-time quantitative PCR (RT-PCR) showed that PKPs-1 significantly increased the expression of insulin receptor substrate-1 (IRS-1), phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT), indicating that PKPs-1 regulates glucose metabolism by activating the PI3K/AKT signaling pathway. This study provides new insights for investigating the hypoglycemic effects of PKPs-1 and suggests that PKPs-1 could be a promising functional food or medicine for treating T2DM.

Identification of Tibetan medicine Dida based on DNA barcoding.

The purpose of this study was to test the ability of DNA barcoding to identify the herbal raw trade of Tibetan medicine Dida in China. A reference database for plant-material DNA barcodes was successfully constructed and used to identify 36 commercially samples of Dida collected from Southwest China. The ITS sequence was amplified from these samples and the efficiency of the PCR amplification of ITS was 100%. The DNA sequencing results revealed that 3 samples (8.3%) were authenticated as Swertia chirayita, 2 sequences (5.6%) were authenticated as Swertia mussotii, 3 sequences (8.3%) were authenticated as Swertia ciliata, as recorded in the Tibetan Pharmacopeia. The other samples were authenticated as adulterants and all of them originated from common plants belonging to Saxifraga, Swertia and Halenia. This result indicates Dida pieces that are available in the market have complex origins and may indicate a potential safety issue and DNA barcoding is a convenient tool for market supervision.

Evaluation of Octaethyl-7,17-dioxobacteriochlorin as a Ligand for Transition Metals.

The propensity of octaethyl-7,17-dioxobacteriochlorin toward the formation of transition metal complexes was evaluated. A variety of MII ions (M = Co, Ni, Cu, Zn, Pd, Ag, and Cd) and Fe(III) could be inserted using standard methodologies or, more often, using more forcing conditions. The stable products were spectroscopically characterized. The solid-state structures of the Ni(II), Cu(II), Pd(II), and Ag(II) complexes could also be determined by single crystal X-ray diffractometry, whereby the [7,17-dioxobacteriochlorinato] chromophore was found to be largely planar in all cases. The rate of Zn(II) insertion into octaethyl-7,17-dioxobacteriochlorin was less than half that into the corresponding 7-oxochlorin, which itself was about half the rate into the parent octaethylporphyrin. These rate differences reflect the relative decreased basicity of the ß-oxo-substituted chromophores and possibly also their decreased conformational flexibility. We compare the basicity of the dioxobacteriochlorin to that of a range of related products of varying reduction state (porphyrin, chlorin, bacteriochlorin), an isomer, and the absence or presence of oxo-functionality, like oxochlorin, chlorin, oxobacteriochlorins, and bacteriochlorin, quantifying the effects of these macrocycle modifications. The work rationalizes earlier reports of the inability of tolyporphin A, a natural product possessing a 7,17-dioxobacteriochlorin chromophore, to form metal complexes and provide a more quantitative understanding of the degree of modulation that ß-oxo groups have on the coordination properties of porphyrinoids.

Structure-function relationship between Bruch's membrane opening-minimum rim width and perimetry in open-angle glaucoma subtypes.

PURPOSE: To seek the threshold value of Bruch's membrane opening-minimum rim width (BMO-MRW) where visual field (VF) damage occurs in open-angle glaucoma (OAG) and explore whether there are structural differences between primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). METHODS: We recruited 83 healthy and 106 glaucoma (49 with POAG and 57 with NTG) subjects for this study. All subjects underwent optical coherence tomography (OCT), BMO-MRW scans, and Humphrey visual field (VF) analyzer examination. Global and sectoral BMO-MRW was correlated with the corresponding VF according to the Garway-Heath map. Using a broken-stick statistical model, the structure-function relationship of VF values and BMO-MRW, the tipping point where VF defects were associated with a reduction in BMO-MRW and the slopes above and below the tipping point were determined and compared between POAG and NTG. RESULTS: The tipping point of global BMO-MRW for VF impairment was 234.38 µm, 228.09 µm, and 249.68 µm in the OAG, POAG, and NTG groups, respectively. The slope below the tipping point was significantly steeper than the slope above it in all quadrants of each group (p < 0.001). The tipping point in NTG in the inferotemporal and nasal quadrants was smaller than that of POAG, especially in the inferotemporal quadrant. CONCLUSION: In OAG, BMO-MRW loss seems to occur before the onset of perimetric impairment. Compared with POAG, NTG appears to have more severe rim damage, especially in the inferotemporal quadrant at the onset of detectable VF defects.

Effect of context exposure after fear learning on memory generalization in mice.

BACKGROUND: The conditions under which memory generalization occurs are not well understood. Although it is believed that fear memory generalization is gradually established after learning, it is not clear whether experiences soon after learning affect generalization. RESULTS: Using a contextual fear conditioning paradigm in mice, we found that fear memory generalization occurred when mice were exposed to a familiar, unconditioned context soon after fear learning. CONCLUSIONS: Our results suggest that the familiarity of contexts and the timing of their exposure influences memory generalization, which increases our understanding of the mechanisms of generalization.

Rheological and kinetic study of the ultrasonic degradation of locust bean gum in aqueous saline and salt-free solutions.

The ultrasonic degradation of locust bean gum (LBG) in aqueous solutions has been studied at 25°C for ultrasonication times up to 120 min. Although LBG is not a polyelectrolyte, the degradation extent and kinetics were found to be somewhat sensitive to the ionic conditions in solution, and this is attributed to changes in molecular conformation that can occur in different salt environments. Ultrasonic degradation was tracked by rheological measurements that lead to the determination of intrinsic viscosity for the LBG molecules. A kinetic model was also developed and successfully applied to characterize and predict the degradation results.

Indachlorins: nonplanar indanone-annulated chlorin analogues with panchromatic absorption spectra between 300 and 900†nm.

Indaphyrins, pyrrole-modified porphyrins containing a cleaved pyrrole ß,ß'-bond and two annulated indanone moieties, possess unusually broadened and redshifted UV/Vis spectra because of their π-expanded chromophores. The parent free base indaphyrin has been crystallographically characterized, highlighting its strongly ruffled conformation incorporating a helimeric twist. It was shown to be susceptible to regiospecific derivatizations at the opposite side of the ring-cleaved pyrrole (dihydroxylation, followed by functional group transformations of the resulting diol functionality), generating indaphyrin-based chlorin analogues, indachlorins, that incorporate a dihydroxypyrroline, pyrrolindione, oxazolone, or a morpholine moiety. Structural modifications resulted in further broadening and hyper- and bathochromic shifts of the optical spectra, some of which possess a nearly panchromatic absorption between 300 to well above 900 nm. The extents to which these modifications affect their solid-state conformations were analyzed.

Rheological and kinetic study of the ultrasonic degradation of xanthan gum in aqueous solution: effects of pyruvate group.

The influence of the pyruvate group on the efficiency of ultrasonic degradation of xanthan gum in aqueous solution has been studied. Blends of natural and pyruvate-free xanthan gums were ultrasonicated at 20°C for up to 30min and evaluated for molecular-weight degradation by viscometry. Solutions of pure pyruvate-free xanthan exhibited the highest stability to degradation among all blend ratios studied. Removing the pyruvate group is believed to enable the molecular chains to adopt a more compact conformation, which renders the polymer less susceptible to ultrasonication. In addition, the effects of salt on ultrasonic degradation efficiency were studied by using 0.1, 10(-2), or 10(-4)M of NaCl or Na2SO4 in solution prior to ultrasonication. A degradation kinetics model was developed to quantify the degradation behavior. The absence of pyruvate groups renders the xanthan gum less sensitive to the influence of salt, and hence decreases the ultrasonic degradation efficiency.