Confinement of Luminescent Guests in Metal-Organic Frameworks: Understanding Pathways from Synthesis and Multimodal Characterization to Potential Applications of LG@MOF Systems.

This review gives an authoritative, critical, and accessible overview of an emergent class of fluorescent materials termed "LG@MOF", engineered from the nanoscale confinement of luminescent guests (LG) in a metal-organic framework (MOF) host, realizing a myriad of unconventional materials with fascinating photophysical and photochemical properties. We begin by summarizing the synthetic methodologies and design guidelines for representative LG@MOF systems, where the major types of fluorescent guest encompass organic dyes, metal ions, metal complexes, metal nanoclusters, quantum dots, and hybrid perovskites. Subsequently, we discuss the methods for characterizing the resultant guest-host structures, guest loading, photophysical properties, and review local-scale techniques recently employed to elucidate guest positions. A special emphasis is paid to the pros and cons of the various methods in the context of LG@MOF. In the following section, we provide a brief tutorial on the basic guest-host phenomena, focusing on the excited state events and nanoscale confinement effects underpinning the exceptional behavior of LG@MOF systems. The review finally culminates in the most striking applications of LG@MOF materials, particularly the "turn-on" type fluorochromic chemo- and mechano-sensors, noninvasive thermometry and optical pH sensors, electroluminescence, and innovative security devices. This review offers a comprehensive coverage of general interest to the multidisciplinary materials community to stimulate frontier research in the vibrant sector of light-emitting MOF composite systems.

Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy.

OBJECTIVES: Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily. MATERIALS AND METHODS: Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase. RESULTS: 45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2. CONCLUSIONS: This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC. CLINICAL RELEVANCE: This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

BACKGROUND: Presbyopia occurs when the lens of the eyes loses its elasticity leading to loss of accommodation. The lens may also progress to develop cataract, affecting visual acuity and contrast sensitivity. One option of care for individuals with presbyopia and cataract is the use of multifocal or extended depth of focus intraocular lens (IOL) after cataract surgery. Although trifocal and bifocal IOLs are designed to restore three and two focal points respectively, trifocal lens may be preferable because it restores near, intermediate, and far vision, and may also provide a greater range of useful vision and allow for greater spectacle independence in individuals with presbyopia. OBJECTIVES: To assess the effectiveness and safety of implantation with trifocal versus bifocal IOLs during cataract surgery among people with presbyopia. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2022, Issue 3); Ovid MEDLINE; Embase.com; PubMed; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 31 March 2022.  SELECTION CRITERIA: We included randomized controlled trials that compared trifocal and bifocal IOLs among participants 30 years of age or older with presbyopia undergoing cataract surgery. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology and graded the certainty of the body of evidence according to the GRADE classification. MAIN RESULTS: We identified seven studies conducted in Europe and Turkey with a total of 331 participants. All included studies assessed visual acuity using a logarithm of the minimum angle of resolution (LogMAR chart). Of them, six (86%) studies assessed uncorrected distance visual acuity (the primary outcome of this review). Some studies also examined our secondary outcomes including uncorrected near, intermediate, and best-corrected distance visual acuity, as well as contrast sensitivity. Study characteristics All participants had bilateral cataracts with no pre-existing ocular pathologies or ocular surgery. Participants' mean age ranged from 55 to 74 years. Three studies reported on gender of participants, and they were mostly women. We assessed all of the included studies as being at unclear risk of bias for most domains. Two studies received financial support from manufacturers of lenses evaluated in this review, and at least one author of another study reported receiving payments for delivering lectures with lens manufacturers. Findings All studies compared trifocal versus bifocal IOL implantation on visual acuity outcomes measured on a LogMAR scale. At one year, trifocal IOL showed no evidence of effect on uncorrected distance visual acuity (mean difference (MD) 0.00, 95% confidence interval (CI) -0.04 to 0.04; I2 = 0%; 2 studies, 107 participants; low-certainty evidence) and uncorrected near visual acuity (MD 0.01, 95% CI -0.04 to 0.06; I2 = 0%; 2 studies, 107 participants; low-certainty evidence). Trifocal IOL implantation may improve uncorrected intermediate visual acuity at one year (MD -0.16, 95% CI -0.22 to -0.10; I2 = 0%; 2 studies, 107 participants; low-certainty evidence), but showed no evidence of effect on best-corrected distance visual acuity at one year (MD 0.00, 95% CI -0.03 to 0.04; I2 = 0%; 2 studies, 107 participants; low-certainty evidence). No study reported on contrast sensitivity or quality of life at one-year follow-up. Data from one study at three months suggest that contrast sensitivity did not differ between groups under photopic conditions, but may be worse in the trifocal group in one of the four frequencies under mesopic conditions (MD -0.19, 95% CI -0.33 to -0.05; 1 study; I2 = 0%, 25 participants; low-certainty evidence). One study examined vision-related quality of life using the 25-item National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) at six months, and suggested no evidence of a difference between trifocal and bifocal IOLs (MD 1.41, 95% CI -1.78 to 4.60; 1 study, 40 participants; low-certainty evidence). Adverse events Adverse events reporting varied among studies. Of five studies reporting information on adverse events, two studies observed no intraoperative and postoperative complications or no posterior capsular opacification at six months. One study reported that glare and halos were similar to the preoperative measurements. One study reported that 4 (20%) and 10 (50%) participants had glare complaints at 6 months in trifocal and bifocal group, respectively (risk ratio 0.40, 95% CI 0.15 to 1.07; 40 participants). One study reported that four eyes (11.4%) in the bifocal group and three eyes (7.5%) in the trifocal group developed significant posterior capsular opacification requiring YAG capsulotomy at one year. The certainty of the evidence for adverse events was low. AUTHORS' CONCLUSIONS: We found low-certainty of evidence that compared with bifocal IOL, implantation of trifocal IOL may improve uncorrected intermediate visual acuity at one year. However, there was no evidence of a difference between trifocal and bifocal IOL for uncorrected distance visual acuity, uncorrected near visual acuity, and best-corrected visual acuity at one year. Future research should include the comparison of both trifocal IOL and specific bifocal IOLs that correct intermediate visual acuity to evaluate important outcomes such as contrast sensitivity, quality of life, and vision-related adverse effects.

Modulating the spectroscopy and dynamics of a proton-transfer dye by functionalizing with phenyl groups.

Molecules undergoing excited-state proton transfer (ESPT) reactions are among the most interesting systems from spectroscopic and photophysical viewpoints. These molecules can be further functionalized with electron donating or accepting groups, inducing intramolecular charge transfer (ICT) events, which might be coupled to the ESIPT ones, conferring them with different spectroscopic and photophysical properties, which can be essential to implement the related materials in many key scientific and technological fields. Here, we report new benzimidazole derivatives that are functionalized with a phenyl group, 2-(5,10-diphenyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenol (DP-HPPI), and its methylated equivalent, 2-(2-methoxyphenyl)-5,10-diphenyl-1H-phenanthro[9,10-d]imidazole (DP-MPPI). The results prove that these molecules in solutions undergo an ultrafast ICT (400-700 fs) reaction. Additionally, DP-HPPI also undergoes a reversible ESIPT process in dichloromethane. However, this is precluded in acetonitrile due to the involvement of intermolecular H-bonds in this solvent. These results provide key insights into the development of proton-transfer materials with bespoke spectral and photodynamical properties.

Is the use of a potassium nitrate dentifrice effective in reducing tooth sensitivity related to in-office bleaching? A randomized triple-blind clinical trial.

OBJECTIVE: The aims of this study were to evaluate whether the use of a dentifrice containing 5% potassium nitrate (KNO3 ) prior to and during in-office dental bleaching reduces bleaching-induced tooth sensitivity and affects bleaching efficiency. MATERIALS AND METHODS: Thirty-eight individuals were randomly distributed into two groups (n = 19). The experimental group performed toothbrushing using a dentifrice containing 5% KNO3 , one week before treatment and before the first and second bleaching sessions. In the control group, a placebo dentifrice without KNO3 was applied as described for the first group. Tooth sensitivity was recorded on visual analog scales (VAS) and numeric rating scales (NRS) immediately and up to 48 h after bleaching sessions. Color change at different time intervals, was evaluated with shade guide units (∆SGU) and a digital spectrophotometer (∆E CIELab 1976 and CIEDE2000) at baseline and 7, 15, and 30 days post-bleaching. Mann-Whitney test and t-test were used to evaluate TS intensity for NRS and VAS scales, respectively, and T-test was used for color difference evaluation. RESULTS: No significant difference in tooth sensitivity's absolute risk and intensity were observed between tested groups in any evaluated treatment time for NRS (p = 0.91) or VAS scales (p = 0.48). T-test showed no significant difference in both ∆E and ∆SGU tooth color among the experimental and control groups during the different evaluation times (p = 0.27). CONCLUSION: The use of a dentifrice containing 5% KNO3 does not prevent post-operatory tooth sensitivity but allows the same whitening efficiency as a regular dentifrice. CLINICAL SIGNIFICANCE: The use of a dentifrice-containing KNO3 did not prevent bleaching-induced tooth sensitivity when high-concentrated hydrogen peroxide was used for in-office bleaching.

The influence of red blood cell deformability on hematocrit profiles and platelet margination.

The influence of red blood cell (RBC) deformability in whole blood on platelet margination is investigated using confocal microscopy measurements of flowing human blood and cell resolved blood flow simulations. Fluorescent platelet concentrations at the wall of a glass chamber are measured using confocal microscopy with flowing human blood containing varying healthy-to-stiff RBC fractions. A decrease is observed in the fluorescent platelet signal at the wall due to the increase of stiffened RBCs in flow, suggesting a decrease of platelet margination due to an increased fraction of stiffened RBCs present in the flow. In order to resolve the influence of stiffened RBCs on platelet concentration at the channel wall, cell-pair and bulk flow simulations are performed. For homogeneous collisions between RBC pairs, a decrease in final displacement after a collision with increasing membrane stiffness is observed. In heterogeneous collisions between healthy and stiff RBC pairs, it is found that the stiffened RBC is displaced most. The influence of RBC deformability on collisions between RBCs and platelets was found to be negligible due to their size and mass difference. For a straight vessel geometry with varying healthy-to-stiff RBC ratios, a decrease was observed in the red blood cell-free layer and platelet margination due to an increase in stiffened RBCs present in flow.

Near-Field Infrared Nanospectroscopy Reveals Guest Confinement in Metal-Organic Framework Single Crystals.

Metal-organic frameworks (MOFs) can provide exceptional porosity for molecular guest encapsulation useful for emergent applications in sensing, gas storage, drug delivery, and optoelectronics. Central to the realization of such applications, however, is the successful incorporation of a functional guest confined within the host framework. Here, we demonstrate, for the first time, the feasibility of scattering-type scanning near-field optical microscopy (s-SNOM) and nano-Fourier transform infrared (nanoFTIR) spectroscopy, in concert with density functional theory (DFT) calculations to reveal the vibrational characteristics of the Guest@MOF systems. Probing individual MOF crystals, we pinpoint the local molecular vibrations and, thus, shed new light on the host-guest interactions at the nanoscale. Our strategy not only confirms the successful encapsulation of luminescent guest molecules in the porous host framework in single crystals but also further provides a new methodology for nanoscale-resolved physical and chemical identification of wide-ranging framework materials and designer porous systems for advanced applications.

Interrogating the Behaviour of a Styryl Dye Interacting with a Mesoscopic 2D-MOF and Its Luminescent Vapochromic Sensing.

In this contribution, we report on the solid-state-photodynamical properties and further applications of a low dimensional composite material composed by the luminescent trans-4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) dye interacting with a two-dimensional-metal organic framework (2D-MOF), Al-ITQ-HB. Three different samples with increasing concentration of DCM are synthesized and characterized. The broad UV-visible absorption spectra of the DCM/Al-ITQ-HB composites reflect the presence of different species of DCM molecules (monomers and aggregates). In contrast, the emission spectra are narrower and exhibit a bathochromic shift upon increasing the DCM concentration, in agreeance with the formation of adsorbed aggregates. Time-resolved picosecond (ps)-experiments reveal multi-exponential behaviors of the excited composites, further confirming the heterogeneous nature of the samples. Remarkably, DCM/Al-ITQ-HB fluorescence is sensitive to vapors of electron donor aromatic amine compounds like aniline, methylaniline, and benzylamine due to a H-bonding-induced electron transfer (ET) process from the analyte to the surface-adsorbed DCM. These findings bring new insights on the photobehavior of a well-known dye when interacting with a 2D-MOF and its possible application in sensing aniline derivatives.

Thiophene-Based Covalent Organic Frameworks: Synthesis, Photophysics and Light-Driven Applications.

Porous crystalline materials, such as covalent organic frameworks (COFs), have emerged as some of the most important materials over the last two decades due to their excellent physicochemical properties such as their large surface area and permanent, accessible porosity. On the other hand, thiophene derivatives are common versatile scaffolds in organic chemistry. Their outstanding electrical properties have boosted their use in different light-driven applications (photocatalysis, organic thin film transistors, photoelectrodes, organic photovoltaics, etc.), attracting much attention in the research community. Despite the great potential of both systems, porous COF materials based on thiophene monomers are scarce due to the inappropriate angle provided by the latter, which hinders its use as the building block of the former. To circumvent this drawback, researchers have engineered a number of thiophene derivatives that can form part of the COFs structure, while keeping their intrinsic properties. Hence, in the present minireview, we will disclose some of the most relevant thiophene-based COFs, highlighting their basic components (building units), spectroscopic properties and potential light-driven applications.

Trifocal intraocular lenses versus bifocal intraocular lenses after cataract extraction among participants with presbyopia.

BACKGROUND: Presbyopia occurs when the lens of the eyes loses its elasticity leading to loss of accommodation. The lens may also progress to develop cataract, affecting visual acuity and contrast sensitivity. One option of care for individuals with presbyopia and cataract is the use of multifocal or extended depth of focus intraocular lens (IOL) after cataract surgery. Although trifocal and bifocal IOLs are designed to restore three and two focal points respectively, trifocal lens may be preferable because it restores near, intermediate, and far vision, and may also provide a greater range of useful vision and allow for greater spectacle independence in individuals with presbyopia. OBJECTIVES: To assess the effectiveness and safety of implantation with trifocal versus bifocal IOLs during cataract surgery among participants with presbyopia. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 9); Ovid MEDLINE; Embase.com; PubMed; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 26 September 2019. We searched the reference lists of the retrieved articles and the abstracts from the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO) for the years 2005 to 2015. SELECTION CRITERIA: We included randomized controlled trials that compared trifocal and bifocal IOLs among participants 30 years or older with presbyopia undergoing cataract surgery. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodology. MAIN RESULTS: We identified five studies conducted in Europe with a total of 175 participants. All five studies assessed uncorrected distance visual acuity (primary outcome of the review), while some also examined our secondary outcomes including uncorrected near, intermediate, and best-corrected distance visual acuity, as well as contrast sensitivity. Study characteristics All participants had bilateral cataracts with no pre-existing ocular pathologies or ocular surgery. Participants' mean age ranged from 58 to 64 years. Only one study reported on gender of participants, and they were mostly women. We assessed all the included studies as being at unclear risk of bias for most domains. Two studies received financial support from manufacturers of lenses evaluated in this review, and at least one author of another study reported receiving payments for delivering lectures with lens manufacturers. Findings All studies compared trifocal versus bifocal IOL implantation on visual acuity outcomes measured on a LogMAR scale. At one year, trifocal IOL showed no evidence of effect on uncorrected distance visual acuity (mean difference (MD) 0.00, 95% confidence interval (CI) -0.04 to 0.04; I2 = 0%; 2 studies, 107 participants; low-certainty evidence) and uncorrected near visual acuity (MD 0.01, 95% CI -0.04 to 0.06; I2 = 0%; 2 studies, 107 participants; low-certainty evidence). Trifocal IOL implantation may improve uncorrected intermediate visual acuity at one year (MD -0.16, 95% CI -0.22 to -0.10; I2= 0%; 2 studies, 107 participants; low-certainty evidence), but showed no evidence of effect on best-corrected distance visual acuity at one year (MD 0.00, 95% CI -0.03 to 0.04; I2= 0%; 2 studies, 107 participants; low-certainty evidence). No study reported on contrast sensitivity or quality of life at one-year follow-up. Data from one study at three months suggest that contrast sensitivity did not differ between groups under photopic conditions, but may be worse in the trifocal group in one of the four frequencies under mesopic conditions (MD -0.19, 95% CI -0.33 to -0.05; 1 study; I2 = 0%, 25 participants; low-certainty evidence). In two studies, the investigators observed that participants' satisfaction or spectacle independence may be higher in the trifocal group at six months, although another study found no evidence of a difference in participant satisfaction or spectacle independence between groups. Adverse events Adverse events reporting varied among studies. Two studies reported information on adverse events at one year. One study reported that participants showed no intraoperative or postoperative complications, while the other study reported that four eyes (11.4%) in the bifocal and three eyes (7.5%) in the trifocal group developed significant posterior capsular opacification requiring YAG capsulotomy. The certainty of the evidence was low. AUTHORS' CONCLUSIONS: There is low-certainty of evidence that compared to bifocal IOL, implantation of trifocal IOL may improve uncorrected intermediate visual acuity at one year. However, there is no evidence of a difference between trifocal and bifocal IOL for uncorrected distance visual acuity, uncorrected near visual acuity, and best-corrected visual acuity at one year. Future research should include the comparison of both trifocal IOL and specific bifocal IOLs that correct intermediate visual acuity to evaluate important outcomes such as contrast sensitivity and quality of life.

Dentin moisture does not influence postoperative sensitivity in posterior restorations: A double-blind randomized clinical trial.

PURPOSE: This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS) in posterior restorations using a simplified etch-and-rinse adhesive, until 12 months of clinical service. METHODS: 90 restorations were inserted in 45 patients to treat carious lesions or to replace existing posterior restorations with a depth ≥ 3 mm. After cavity preparation, the simplified etch-and-rinse adhesive (Adper Single Bond 2) was applied on dry or wet dentin followed by a bulk-fill resin composite (Filtek Bulk Fill) under rubber dam isolation. The patient's spontaneous and stimulated POS was evaluated at baseline and after 7 days, 6 months, and 12 months of clinical evaluation. The secondary parameters (marginal discoloration, marginal adaptation, fracture and recurrence of caries) were evaluated by World Dental Federation (FDI) criteria after 7 days, 6 and 12 months of clinical evaluation. RESULTS: No significant spontaneous and stimulated POS was observed when dry and wet dentin were compared (P> 0.05). A significant and higher risk of spontaneous POS (18.6%; 95% CI 9.7 to 32.6) occurred up to 48 hours after restoration placement for both groups when compared to all evaluation times (P< 0.03). However, the intensity of POS was mild at up to 48 hours with a difference between the dry and wet dentin groups (P> 0.79). When secondary parameters were evaluated, no significant difference between the groups were observed (P> 0.05). CLINICAL SIGNIFICANCE: The moisture level of the dentin substrate in posterior restorations does not influence POS in bulk-fill resin composite posterior restorations when associated with an etch-and-rinse ethanol-based adhesive system.

Femto- to Millisecond Time-Resolved Photodynamics of a Double-Functionalized Push-Pull Organic Linker: Potential Candidate for Optoelectronically Active MOFs.

The design of improved organic linkers for the further engineering of smarter metal-organic framework (MOF) materials has become a paramount task for a wide number of material scientists. In this report, a luminescent double-functionalized push-pull (electron donor-acceptor) archetype organic molecule, dimethyl 4-amino-8-cyanonaphthalene-2,6-dicarboxylate (Me2CANADC), has been synthesized and characterized. The optical steady-state properties of Me2CANADC are strongly influenced by the surrounding environment as a direct consequence of its strong charge transfer (CT) character. The relaxation from its first electronically excited singlet state follows a double pathway: (1) on one side deactivating from its local excited (LE) state in the sub-picosecond or picosecond time domain, and (2) on the other side undergoing an ultrafast intramolecular charge transfer (ICT) reaction that is slowing down in viscous solvents. The deactivation to the ground state of these species with CT character is the origin of the Me2CANADC luminescence, and they present solvent-dependent lifetime values ranging from 8 to 18 ns. The slow photodynamics of Me2CANADC unveils the coexistence of a non-emissive triplet excited state and the formation of a long-lived charge separated state (2 µs). These observations highlight the promising optical properties of Me2CANADC linker, opening a window for the design of new functional MOFs with huge potential to be applied in the fields of luminescent sensing and optoelectronics.

Pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy for giant retinal tear.

BACKGROUND: A giant retinal tear (GRT) is a full-thickness neurosensory retinal break extending for 90° or more in the presence of a posterior vitreous detachment. OBJECTIVES: To evaluate the effectiveness and safety of pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy alone for eyes with giant retinal tear. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 8), which contains the Cochrane Eyes and Vision Trials Register; Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Literature on Health Sciences (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in our electronic search. We last searched the electronic databases on 16 August 2018. SELECTION CRITERIA: We included only randomized controlled trials (RCTs) comparing pars plana vitrectomy combined with scleral buckle versus pars plana vitrectomy alone for giant retinal tear regardless of age, gender, lens status (e.g. phakic or pseudophakic eyes) of the affected eye(s), or etiology of GRT among participants enrolled in these trials. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed titles and abstracts, then full-text articles, using Covidence. Any differences in classification between the two review authors were resolved through discussion. Two review authors independently abstracted data and assessed risk of bias of included trials. MAIN RESULTS: We found two RCTs in abstract format (105 participants randomized). Neither RCT was published in full. Based on the data presented in the abstracts, scleral buckling might be beneficial (relative risk of re-attachement ranged from 3.0 to 4.4), but the findings are inconclusive due to a lack of peer reviewed publication and insufficient information for assessing risk of bias. AUTHORS' CONCLUSIONS: We found no conclusive evidence from RCTs on which to base clinical recommendations for scleral buckle combined with pars plana vitrectomy for giant retinal tear. RCTs are clearly needed to address this evidence gap. Such trials should be randomized, and patients should be classified by giant retinal tear characteristics (extension (90º, 90º to 180º, > 180º), location (oral, anterior, posterior to equator)), proliferative vitreoretinopathy stage, and endotamponade. Analysis should include both short-term (three months and six months) and long-term (one year to two years) outcomes for primary retinal reattachment, mean change in best corrected visual acuity, study eyes that required second surgery for retinal reattachment, and adverse events such as elevation of intraocular pressure above 21 mmHg, choroidal detachment, cystoid macular edema, macular pucker, proliferative vitreoretinopathy, and progression of cataract in initially phakic eyes.

Presence of Rigid Red Blood Cells in Blood Flow Interferes with the Vascular Wall Adhesion of Leukocytes.

The symptoms of many blood diseases can often be attributed to irregularities in cellular dynamics produced by abnormalities in blood cells, particularly red blood cells (RBCs). Contingent on the disease and its severity, RBCs can be afflicted with increased membrane rigidity as seen in malaria and sickle cell disease. Despite this understanding, little experimental work has been conducted toward understanding the effect of RBC rigidity on cellular dynamics in physiologic blood flow. Though many have computationally modeled complex blood flow to postulate how RBC rigidity may disrupt normal hemodynamics, to date, there lacks a clear understanding of how rigid RBCs affect the blood cell segregation behavior in blood flow, known as margination, and the resulting change in the adhesion of white blood cells (WBCs). In this work, we utilized an in vitro blood flow model to examine how different RBC rigidities and volume fractions of rigid RBCs impact cell margination and the downstream effect on white blood cell (WBC) adhesion in blood flow. Healthy RBC membranes were rigidified and reconstituted into whole blood and then perfused over activated endothelial cells under physiologically relevant shear conditions. Rigid RBCs were shown to reduce WBC adhesion by up to 80%, contingent on the RBC rigidity and the fraction of treated RBCs present in blood flow. Furthermore, the RBC core was found to be slightly expanded with the presence of rigid RBCs, by up to ∼30% in size fully composed of rigid RBCs. Overall, the obtained results demonstrate an impact of RBC rigidity on cellular dynamics and WBC adhesion, which possibly contributes to the pathological understanding of diseases characterized by significant RBC rigidity.

Spectroscopy and dynamics of dehydrobenzo[12]annulene derivatives possessing peripheral carboxyphenyl groups: theory and experiment.

In this work, we report on the results of theoretical and experimental studies of a series of dehydrobenzoannulene (DBA) derivatives (Nu-T12 [5,6,11,12,17,18-hexadehydrotribenzo[a,e,i]cyclododecene], T12-COOMe [5,6,11,12,17,18-hexadehydro-2,3,8,9,14,15-hexakis(4-methoxycarbonylphenyl)tribenzo[a,e,i]cyclododecene] and T12-COOH [5,6,11,12,17,18-hexadehydro-2,3,8,9,14,15-hexakis(4-carboxyphenyl)tribenzo[a,e,i]cyclododecene]) in N,N'-dimethylformamide (DMF) solutions. The theoretical and experimental findings show that the S0 → S1 transition of these molecules is forbidden. Time-resolved spectroscopy measurements determined a lifetime of ∼100 ps of the transition from the first electronical excited (S1) state. These molecules also emit through charge transfer (CT) species, with lifetimes of ∼1 and ∼4.5 ns. In addition to this, Nu-T12 and T12-COOMe in DMF solutions exhibit an emission from their triplet state in 35 and 24.5 ns, respectively. However, T12-COOH strongly interacts through H-bonds with DMF molecules, leading to the formation of new species having a proton-transferred character, whose emission spectrum is red-shifted and its lifetime from the S1 state is ∼25 ns. Using nanosecond (ns) flash photolysis, we also observed the presence of non-emissive triplet states, in addition to the emissive ones. The theoretical calculations suggest that this non-radiative triplet state originates from a CT structure of the emissive triplet one. The new findings presented here elucidate the photobehaviour of three DBA derivatives of relevance to crystalline Hydrogen-Bonded Organic Framework (HOF) materials. The photophysical data provide a strong basis to explore and to better understand the photodynamics of HOF crystals.

Synthesis of Ce2O2S and Gd2(1-y)Ce2yO2S Nanoparticles and Reactivity from in Situ X-ray Absorption Spectroscopy and X-ray Photoelectron Spectroscopy.

Lanthanide oxysulfide nanoparticles have recently attracted interest in view of their potential applications, such as lighting devices and MRI contrast agents, which requires a good stability in air and a controlled surface. In order to address these issues, in this work, air-sensitive Ce2O2S nanoparticles of hexagonal shape were successfully prepared and characterized under inert conditions. Bimetallic Gd2(1-y)Ce2yO2S nanoparticles of similar shape and size were also synthesized for the whole composition range (y from 0 to 1). X-ray diffraction structural data are found to follow Vegard's law up to y = 0.4, which is attributed to the loss of stability in air of Ce-rich nanocrystals beyond this threshold. This picture is supported by X-ray absorption spectra taken at the S K-edge and Ce L3-edge that show the partial oxidation of sulfide species and of CeIII to CeIV in the presence of air or water. A complementary near-ambient-pressure X-ray photoelectron spectroscopy study shows that at least two types of oxidized sulfur species form on the nanoparticle surface. Even in Gd2O2S nanoparticles that are generally considered to be air-stable, we found that sulfide ions are partially oxidized to sulfate in air. These results unveil the physicochemical mechanisms responsible for the surface reactivity of lanthanide oxysulfides nanoparticles in air.

Effect of MDP-containing Silane and Adhesive Used Alone or in Combination on the Long-term Bond Strength and Chemical Interaction with Lithium Disilicate Ceramics.

PURPOSE: To evaluate the effect of a silane and an adhesive containing MDP, used alone or combined in the same solution, on the microshear bond strength (µSBS) to lithium disilicate ceramics immediately and after 1-year water storage, and compare the bond strength results with the Raman spectra of the treated lithium disilicate surfaces. MATERIALS AND METHODS: A total of 30 CAD/CAM blocks of lithium disilicate (LD; IPS e.max CAD) were cut into four square sections (6 x 6 x 6 mm; n = 60 per group) and processed as recommended by the manufacturer. The LD specimens were divided into 12 groups according to the following independent variables: silane coupling agent (no silane; silane without 10-MDP [MBS, Monobond S]; silane with 10-MDP [MB+, Monobond Plus]) and adhesive + luting composite (no adhesive + Enforce; no adhesive + RelyX Ultimate; Prime & Bond Elect [PBE], a silane- and MDP-free universal adhesive + Enforce; Scotchbond Universal Adhesive [SBU], a silane- and MDP-containing universal adhesive + RelyX Ultimate). After each treatment, cylindrical, transparent matrices were filled with a luting composite and light cured. Specimens were stored in water (37°C for 24 h or 1 year) and submitted to the microshear bond strength (µSBS) test. The failure pattern and µSBS were statistically evaluated (α = 0.05). In addition, specimens were examined for chemical interaction using Raman spectroscopy. RESULTS: The use of the adhesive PBE alone showed higher mean µSBS compared with both groups with silane (MSB or MB+) without PBE (p < 0.001) at 24 h. The use of the SBU adhesive or MBS silane alone, as well as MB+ associated with SBU, showed higher mean µSBS (p < 0.001) at 24 h. After 1-year water storage, all groups showed a significant decrease in mean µSBS. However, the application of PBE or SBU associated with MB+ silane showed higher 1-year mean µSBS (p < 0.001). In terms of chemical interaction, when silane (MSB or MB+) was applied, only a slight decrease of Si-O peaks occurred. Otherwise, when PBE or SBU adhesives were applied, methacrylate peaks were only observed in the SBU groups. CONCLUSION: The best results in terms of bond strength after water storage were obtained when an MDP-containing silane was associated with a universal adhesive. The use of a simplified bonding protocol that includes either a silane or a universal adhesive is not recommended.

Geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples, and its possible relationship with the prevalence of enamel fluorosis in children in four municipalities of the department of Huila (Colombia).

Fluoride is an element that affects teeth and bone formation in animals and humans. Though the use of systemic fluoride is an evidence-based caries preventive measure, excessive ingestion can impair tooth development, mainly the mineralization of tooth enamel, leading to a condition known as enamel fluorosis. In this study, we investigated the geochemical characterization of fluoride in water, table salt, active sediment, rock and soil samples in four endemic enamel fluorosis sentinel municipalities of the department of Huila, Colombia (Pitalito, Altamira, El Agrado and Rivera), and its possible relationship with the prevalence of enamel fluorosis in children. The concentration of fluoride in drinking water, table salt, active sediment, rock, and soil was evaluated by means of an ion selective electrode and the geochemical analyses were performed using X-ray fluorescence. Geochemical analysis revealed fluoride concentrations under 15 mg/kg in active sediment, rock and soil samples, not indicative of a significant delivery to the watersheds studied. The concentration of fluoride in table salt was found to be under the inferior limit (less than 180 µg/g) established by the Colombian regulations. Likewise, exposure doses for fluoride water intake did not exceed the recommended total dose for all ages from 6 months. Although the evidence does not point out at rocks, soils, fluoride-bearing minerals, fluoridated salt and water, the hypothesis of these elements as responsible of the current prevalence of enamel fluorosis cannot be discarded since, aqueducts might have undergone significant changes overtime.

Competitive Excimer Formation and Energy Transfer in Zr-Based Heterolinker Metal-Organic Frameworks.

The spectroscopy and dynamics of a series of Zr-based MOFs in dichloromethane suspension are reported. These Zr-NADC MOFs were constructed by using different mixtures of 2,6-naphthalenedicarboxylate (NDC) and 4-amino-2,6-naphthalenedicarboxylate (NADC) as organic linkers. The fraction of NADC relative to NDC in these heterolinker MOFs ranges from 2 to 35 %. The results indicate two competitive photoprocesses: NDC excimer formation and an energy transfer (ET) from excited NDC linkers to NADC linkers. Increasing the fraction of NADC linkers in the Zr-NADC nanostructure decreases the mean time constant of NDC excimer formation, while the NADC emission intensity experiences a drop at the highest fraction of this linker in the MOF. The first observation is explained by an increase in the energy-transfer probability between the two linkers, and the second by emission quenching in the NADC linkers due to ultrafast charge transfer assisted by the amino group. Femtosecond time-resolved emission studies showed that the ET process (recorded as decaying and rising components) from excited NDC to NADC takes place in 1.2 ps. Direct excitation of the NADC linkers (at 410 nm) shows a decaying, but not rising, component of 250-480 fs, which could reflect the formation of a nonemissive charge-separation state. The results show that by using MOFs having heterolinkers it is possible to trigger and tune excimer formation and ET processes.

Spectral and dynamical properties of a Zr-based MOF.

We report on the spectra and dynamics of a Zr-naphthalene dicarboxylic acid (Zr-NDC) MOF in different diluted solvent suspensions and in a concentrated tetrahydrofuran (THF) one. In a diluted diethyl ether (DE) suspension, we observed intraparticle excimer formation between neighboring naphthalene organic linkers, leading to a red-shifted broad band in the emission spectrum and to a dynamics composed of three components τ1 = 650 ps, τ2 = 3.7 ns and τ3 = 13.9 ns, assigned to the excimer photoproduction, monomer and excimer lifetimes, respectively. Furthermore, both absorption and emission spectra show a blue shift in more polar solvents characterized by the solvent polarity function f(ε,n). We also observed changes in the excimer formation time (490-840 ps) probably due to a variation in the MOF structural fluctuation induced by solvent filling. The global fluorescence quantum yield of these suspensions is around 0.30 ± 0.05. At higher concentrations of the MOF particles, we observed the absorption and emission signals of aggregates having an intercrystal excimer formation in ∼ 5 ps in a THF suspension, ∼ 100 times shorter than that observed in a diluted one. Our results give the spectral and dynamical properties of a Zr-NDC MOF in solvent suspensions, opening the way to further studies of these kinds of MOFs interacting with fluorescent dyes for possible photonic applications.