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1.
Intern Med J ; 53(3): 439-442, 2023 03.
Article in English | MEDLINE | ID: mdl-36972990

ABSTRACT

From a personal perspective of an endocrinologist in private practice: Integration of the My Health Record into everyday clinical practice is time- and cost-saving, allows for more accurate record keeping and most importantly improves overall patient care. The main deficiency at present is incomplete uptake by medical specialists in private and public practice, as well as pathology and imaging service providers. We will all reap the benefits as these entities become engaged and contribute towards making this electronic medical record truly universal.


Subject(s)
Electronic Health Records , Physicians , Humans
2.
Future Oncol ; 18(26): 2879-2889, 2022 Aug.
Article in English | MEDLINE | ID: mdl-35852098

ABSTRACT

Prevention of relapse is a major therapeutic challenge and an unmet need for patients with acute myeloid leukemia (AML). Venetoclax is a highly selective, potent, oral BCL-2 inhibitor that induces apoptosis in AML cells. When combined with azacitidine, it leads to prolonged overall survival and rapid, durable remissions in treatment-naive AML patients ineligible for intensive chemotherapy. VIALE-M is a randomized, double-blind, two-arm study to evaluate the safety and efficacy of venetoclax in combination with oral azacitidine (CC-486) as maintenance therapy in patients in complete remission with incomplete blood count recovery after intensive induction and consolidation therapies. The primary end point is relapse-free survival. Secondary outcomes include overall survival, minimal residual disease conversion and improvement in quality-of-life. Trial Registration Number: NCT04102020 (ClinicalTrials.gov).


Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Leukemia, Myeloid, Acute , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Azacitidine/adverse effects , Bridged Bicyclo Compounds, Heterocyclic , Cell Division , Clinical Trials, Phase III as Topic , Humans , Randomized Controlled Trials as Topic , Sulfonamides
3.
Cancers (Basel) ; 13(15)2021 Jul 29.
Article in English | MEDLINE | ID: mdl-34359718

ABSTRACT

Early-onset colorectal cancer has been on the rise in Western populations. Here, we compare patient characteristics between those with early- (<50 years) vs. late-onset (≥50 years) disease in a large multinational cohort of colorectal cancer patients (n = 2193). We calculated descriptive statistics and assessed associations of clinicodemographic factors with age of onset using mutually-adjusted logistic regression models. Patients were on average 60 years old, with BMI of 29 kg/m2, 52% colon cancers, 21% early-onset, and presented with stage II or III (60%) disease. Early-onset patients presented with more advanced disease (stages III-IV: 63% vs. 51%, respectively), and received more neo and adjuvant treatment compared to late-onset patients, after controlling for stage (odds ratio (OR) (95% confidence interval (CI)) = 2.30 (1.82-3.83) and 2.00 (1.43-2.81), respectively). Early-onset rectal cancer patients across all stages more commonly received neoadjuvant treatment, even when not indicated as the standard of care, e.g., during stage I disease. The odds of early-onset disease were higher among never smokers and lower among overweight patients (1.55 (1.21-1.98) and 0.56 (0.41-0.76), respectively). Patients with early-onset colorectal cancer were more likely to be diagnosed with advanced stage disease, to have received systemic treatments regardless of stage at diagnosis, and were less likely to be ever smokers or overweight.

4.
Opt Express ; 28(25): 38008-38028, 2020 Dec 07.
Article in English | MEDLINE | ID: mdl-33379623

ABSTRACT

In near-eye display systems that support three-dimensional (3D) augmented and virtual reality, a central factor in determining the user experience is the size of the eyebox. The eyebox refers to a volume where the eye receives an acceptable view of the image with respect to a set of criteria and thresholds. The size and location of this volume are primarily driven by optical architecture choices in which designers trade-off a number of constraints, such as field of view, image quality, and product design. It is thus important to clearly quantify how design decisions affect the properties of the eyebox. Recent work has started evaluating the eyebox in 3D based purely on optical criteria. However, such analyses do not incorporate perceptual criteria that determine visual quality, which are particularly important for binocular 3D systems. To address this limitation, we introduce the framework of a perceptual eyebox. The perceptual eyebox is the volume where the eye(s) must be located for the user to experience a visual percept falling within a perceptually-defined criterion. We combine optical and perceptual data to characterize an example perceptual eyebox for display visibility in augmented reality. The key contributions in this paper include: comparing the perceptual eyebox for monocular and binocular display designs, modeling the effects of user eye separation, and examining the effects of eye rotation on the eyebox volume.


Subject(s)
Optical Devices , Pattern Recognition, Visual/physiology , Vision, Binocular/physiology , Adult , Female , Humans , Male , User-Computer Interface , Young Adult
5.
Clin Cancer Res ; 26(21): 5609-5620, 2020 11 01.
Article in English | MEDLINE | ID: mdl-32847933

ABSTRACT

PURPOSE: Tumor-associated macrophages correlate with increased invasiveness, growth, and immunosuppression. Activation of the colony-stimulating factor-1 receptor (CSF-1R) results in proliferation, differentiation, and migration of monocytes/macrophages. This phase I study evaluated the immunologic and clinical activity, and safety profile of CSF-1R inhibition with the mAb LY3022855. PATIENTS AND METHODS: Patients with advanced refractory metastatic breast cancer (MBC) or metastatic castration-resistant prostate cancer (mCRPC) were treated with LY3022855 intravenously in 6-week cycles in cohorts: (A) 1.25 mg/kg every 2 weeks (Q2W); (B) 1.0 mg/kg on weeks 1, 2, 4, and 5; (C) 100 mg once weekly; (D)100 mg Q2W. mCRPC patients were enrolled in cohorts A and B; patients with MBC were enrolled in all cohorts. Efficacy was assessed by RECIST and Prostate Cancer Clinical Trials Working Group 2 criteria. RESULTS: Thirty-four patients (22 MBC; 12 mCRPC) received ≥1 dose of LY3022855. At day 8, circulating CSF-1 levels increased and proinflammatory monocytes CD14DIMCD16BRIGHT decreased. Best RECIST response was stable disease in five patients with MBC (23%; duration, 82-302 days) and three patients with mCRPC (25%; duration, 50-124 days). Two patients with MBC (cohort A) had durable stable disease >9 months and a third patient with MBC had palpable reduction in a nontarget neck mass. Immune-related gene activation in tumor biopsies posttreatment was observed. Common any grade treatment-related adverse events were fatigue, decreased appetite, nausea, asymptomatic increased lipase, and creatine phosphokinase. CONCLUSIONS: LY3022855 was well tolerated and showed evidence of immune modulation. Clinically meaningful stable disease >9 months was observed in two patients with MBC.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Breast Neoplasms/drug therapy , Prostatic Neoplasms, Castration-Resistant/drug therapy , Receptor, Macrophage Colony-Stimulating Factor/genetics , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal/adverse effects , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Drug-Related Side Effects and Adverse Reactions/classification , Drug-Related Side Effects and Adverse Reactions/epidemiology , Drug-Related Side Effects and Adverse Reactions/pathology , Female , Humans , Immunologic Factors/administration & dosage , Immunologic Factors/adverse effects , Lipopolysaccharide Receptors/genetics , Male , Middle Aged , Neoplasm Metastasis , Neoplasm Staging , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology , Receptor, Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Receptors, IgG/genetics
6.
Cancer Chemother Pharmacol ; 79(5): 915-922, 2017 May.
Article in English | MEDLINE | ID: mdl-28349167

ABSTRACT

PURPOSE: ABT-414 is an antibody-drug conjugate (ADC) being developed for the treatment of tumors harboring amplification of the epidermal growth factor receptor (EGFR). This study evaluated the potential of ABT-414 to prolong the QT interval as part of the initial phase 1 study (NCT01741727). METHODS: Data from patients who received ABT-414 monotherapy at a dose of 1-4 mg/kg once every 3 weeks or 1 or 1.5 mg/kg weekly for 2 out of every 3 weeks (alternate schedule) by intravenous infusion were included in the analysis of triplicate 12-lead ECGs obtained before dosing and through 168 h after dosing. Data from time-matched pharmacokinetic samples and QT interval assessments were evaluated using linear mixed-effects modeling to determine the effects of ABT-414, total ABT-806, and cysteine-maleimidocaproyl monomethyl auristatin F (Cys-mcMMAF) on the QT interval corrected using Fridericia's formula (QTcF). RESULTS: Fifty-one patients were included in the analyses. ABT-414 had no clinically meaningful effect on QTcF. Using pooled data from doses ≥2 mg/kg, the estimated mean ∆QTcF reached a maximum of 4.30 ms after dosing, with a one-sided 95% upper confidence bound of 8.32 ms. The exposure-response analysis showed no statistically significant relationship between ΔQTcF and the concentration of any analyte (P > 0.05). No patient had a QTcF value >480 ms or a ∆QTcF value >30 ms. CONCLUSIONS: ABT-414 had no clinically meaningful effect on the QTcF interval at doses being evaluated for treatment of patients with solid tumors.


Subject(s)
Antineoplastic Agents/adverse effects , ErbB Receptors/biosynthesis , Long QT Syndrome/chemically induced , Neoplasms/complications , Neoplasms/genetics , Protein Kinase Inhibitors/adverse effects , Adult , Aged , Aged, 80 and over , Antibodies, Monoclonal, Humanized/adverse effects , Biotransformation , Dose-Response Relationship, Drug , Electrocardiography/drug effects , ErbB Receptors/genetics , Female , Humans , Immunoconjugates/adverse effects , Infusions, Intravenous , Male , Middle Aged , Neoplasms/drug therapy
7.
Diabetes Res Clin Pract ; 116: 159-64, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27321331

ABSTRACT

AIMS: To evaluate the achievement of HbA1c targets in patients with type 2 diabetes mellitus in specialist practice. METHODS: This audit was undertaken by members of the S4S Diabetes Informatics Group (DINGO), a consortium of Australian endocrinologists in private practice who contribute de-identified data from their electronic medical record, Audit 4 (Software 4 Specialists, S4S, Australia & New Zealand) for audit purposes. Data from patients with type 2 diabetes was extracted. Inclusion criteria were: initial age<70years, baseline HbA1c>7% (53mmol/mol), with at least another HbA1c recorded in the next 2years, and a minimum of 2years follow-up. Data was analysed using a linear mixed effects model. RESULTS: Of the 4796 patients in the dataset with type 2 diabetes mellitus, 1379 patients fulfilled inclusion criteria. The median age at initial consultation was 57 (49-64)years. The median baseline HbA1c was 8.7 (7.8-9.8)% (72mmol/mol). There was a 1.0% reduction in HbA1c to 7.7 (7.1-8.6)% (61mmol/mol) (p<0.0001) in the first 3-6months following referral, after which there were no further changes. The initial reduction was maintained with minimal loss of control at 4years. By 3-6months, 24% of patients achieved the target HbA1c. CONCLUSIONS: Referral of patients with type 2 diabetes to an endocrinologist reduces HbA1c, and the effect is sustained over the medium term; however only a minority of patients reach targets.


Subject(s)
Diabetes Mellitus, Type 2/blood , Glycated Hemoglobin/analysis , Medical Audit/methods , Female , Humans , Male , Middle Aged
8.
Annu Rev Vis Sci ; 2: 397-435, 2016 10 14.
Article in English | MEDLINE | ID: mdl-28532351

ABSTRACT

Creating realistic three-dimensional (3D) experiences has been a very active area of research and development, and this article describes progress and what remains to be solved. A very active area of technical development has been to build displays that create the correct relationship between viewing parameters and triangulation depth cues: stereo, motion, and focus. Several disciplines are involved in the design, construction, evaluation, and use of 3D displays, but an understanding of human vision is crucial to this enterprise because in the end, the goal is to provide the desired perceptual experience for the viewer. In this article, we review research and development concerning displays that create 3D experiences. And we highlight areas in which further research and development is needed.


Subject(s)
Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Vision, Ocular , Accommodation, Ocular , Cues , Depth Perception , Humans
9.
ACS Appl Mater Interfaces ; 5(7): 2479-84, 2013 Apr 10.
Article in English | MEDLINE | ID: mdl-23474017

ABSTRACT

This manuscript describes the synthesis of uniform monodisperse SnO2-coated gold nanoparticles and examines their colloidal stability as function of pH, with direct comparison to better known and widely used SiO2-coated gold nanoparticles. Aqueous acidic and basic colloidal SnO2-coated and SiO2-coated Au nanoparticle solutions were prepared, and their stability was monitored visually and by UV-vis spectroscopy. Notably, the SnO2-coated Au nanoparticle solutions were stable up to pH 12.5. However, at pH 13 and 14, the SnO2-coated Au nanoparticles underwent aggregation, which could be fully reversed upon neutralization of the solutions. In contrast, the SiO2-coated Au nanoparticle solutions were unstable at pH>10.5, irreversibly producing a precipitate composed of bare Au nanoparticle aggregates having little or no silica coating. Under acidic conditions, sedimentation was observed from both the colloidal SnO2-coated and SiO2-coated Au nanoparticle solutions, but the colloidal solutions could be reconstituted upon neutralization of the acidic solutions. The sedimentation at low pH coincided with the reported isoelectric pH values of SiO2 and SnO2, respectively. From an applications perspective, we are seeking to develop SnO2-coated metal nanoparticles as stable alternatives to the more widely employed SiO2-coated nanoparticles, with a particular emphasis on their use in sensor devices and solar cells.

10.
Proc SPIE Int Soc Opt Eng ; 7863: 78630P1-78630P9, 2011 Feb 15.
Article in English | MEDLINE | ID: mdl-21826254

ABSTRACT

Prolonged use of conventional stereo displays causes viewer discomfort and fatigue because of the vergence-accommodation conflict. We used a novel volumetric display to examine how viewing distance and the sign of the vergence-accommodation conflict affect discomfort and fatigue. In the first experiment, we presented a fixed conflict at short, medium, and long viewing distances. We compared subjects' symptoms in that condition and one in which there was no conflict. We observed more discomfort and fatigue with a given vergence-accommodation conflict at the longer distances. The second experiment compared symptoms when the conflict had one sign compared to when it had the opposite sign at short, medium, and long distances. We observed greater symptoms with uncrossed disparities at long distances and with crossed disparities at short distances. These findings help define comfortable viewing conditions for stereo displays.

11.
J Vis ; 11(8): 11, 2011 Jul 21.
Article in English | MEDLINE | ID: mdl-21778252

ABSTRACT

Recent increased usage of stereo displays has been accompanied by public concern about potential adverse effects associated with prolonged viewing of stereo imagery. There are numerous potential sources of adverse effects, but we focused on how vergence-accommodation conflicts in stereo displays affect visual discomfort and fatigue. In one experiment, we examined the effect of viewing distance on discomfort and fatigue. We found that conflicts of a given dioptric value were slightly less comfortable at far than at near distance. In a second experiment, we examined the effect of the sign of the vergence-accommodation conflict on discomfort and fatigue. We found that negative conflicts (stereo content behind the screen) are less comfortable at far distances and that positive conflicts (content in front of screen) are less comfortable at near distances. In a third experiment, we measured phoria and the zone of clear single binocular vision, which are clinical measurements commonly associated with correcting refractive error. Those measurements predicted susceptibility to discomfort in the first two experiments. We discuss the relevance of these findings for a wide variety of situations including the viewing of mobile devices, desktop displays, television, and cinema.


Subject(s)
Accommodation, Ocular/physiology , Asthenopia/diagnosis , Convergence, Ocular/physiology , Depth Perception/physiology , Vision, Binocular/physiology , Adult , Asthenopia/physiopathology , Humans , Photic Stimulation , Reference Values , Young Adult
12.
J Soc Inf Disp ; 19(3): 271-297, 2011 Mar 01.
Article in English | MEDLINE | ID: mdl-21572544

ABSTRACT

Most stereoscopic displays rely on field-sequential presentation to present different images to the left and right eyes. With sequential presentation, images are delivered to each eye in alternation with dark intervals, and each eye receives its images in counter phase with the other eye. This type of presentation can exacerbate image artifacts including flicker, and the appearance of unsmooth motion. To address the flicker problem, some methods repeat images multiple times before updating to new ones. This greatly reduces flicker visibility, but makes motion appear less smooth. This paper describes an investigation of how different presentation methods affect the visibility of flicker, motion artifacts, and distortions in perceived depth. It begins with an examination of these methods in the spatio-temporal frequency domain. From this examination, it describes a series of predictions for how presentation rate, object speed, simultaneity of image delivery to the two eyes, and other properties ought to affect flicker, motion artifacts, and depth distortions, and reports a series of experiments that tested these predictions. The results confirmed essentially all of the predictions. The paper concludes with a summary and series of recommendations for the best approach to minimize these undesirable effects.

13.
J Am Chem Soc ; 132(51): 18014-6, 2010 Dec 29.
Article in English | MEDLINE | ID: mdl-21125998

ABSTRACT

The addition of 4 equiv of LiN=C-t-Bu(2) to CrCl(3), MoCl(5), and WCl(6) in diethyl ether produced the complexes M(N=C-t-Bu(2))(4) (M = Cr, Mo, W). Single-crystal X-ray diffraction studies revealed that the molecules have flattened tetrahedral geometries with virtual D(2d) symmetry in the solid state. (1)H and (13)C NMR spectra indicated that the complexes are diamagnetic, and a qualitative MO analysis showed that the orthogonal π-donor and -acceptor orbitals of the ketimide ligand cooperatively split the d(xy) and d(z2) orbitals sufficiently to allow spin pairing in the d(xy) orbital. A more sophisticated quantum-mechanical analysis of Cr(N=C-t-Bu(2))(4) using density functional/molecular mechanics methods confirmed the qualitative analysis by showing that the singlet state is 27 kcal/mol more stable than the triplet state.

14.
Dalton Trans ; 39(47): 11439-44, 2010 Dec 21.
Article in English | MEDLINE | ID: mdl-20976345

ABSTRACT

The zinc hydrazide complexes [EtZn(N(SiMe(3))NMe(2))](2), [EtZn(N(Me)NMe(2))](4), and Zn(3)Et(4)(N(Et)NMe(2))(2) were synthesized by allowing excess hydrazine, HN(R)NMe(2), to react with diethyl zinc. The product of the reaction between ZnEt(2) and HN(i-Pr)NMe(2)ortho-metalated 4-(dimethylamino)pyridine (DMAP) at room temperature, producing the complex Zn[(NC(5)H(3)-p-NMe(2))ZnEt(N(i-Pr)NMe(2))](2). At elevated temperatures, Zn(3)Et(4)(N(Et)NMe(2))(2) also ortho-metalated DMAP, but [EtZn(N(Me)NMe(2))](4) did not. Single-crystal X-ray diffraction studies revealed that the hydrazide ligands in [EtZn(N(SiMe(3))NMe(2))](2) act as bridging mono-hapto amide ligands, and in Zn(3)Et(4)(N(Et)NMe(2))(2) and Zn[(NC(5)H(3)-p-NMe(2))ZnEt(N(i-Pr)NMe(2))](2) the hydrazide ligands are di-hapto.

15.
J Vis ; 10(8): 22, 2010 Jul 01.
Article in English | MEDLINE | ID: mdl-20884597

ABSTRACT

Most stereoscopic displays present images at a single focal plane, resulting in "conflicts" between the stimuli to vergence and accommodation. Minimizing these conflicts is beneficial because they can cause distorted depth percepts, visual fatigue, and reduced stereoscopic performance. One proposed solution is to present a sum of images at multiple focal planes and to vary focal depth continuously by distributing image intensity across planes-a technique referred to as depth filtering. We evaluated this digital approximation to real-world variations in focal depth by measuring accommodation responses to depth-filtered stimuli at various simulated distances. Specifically, we determined the maximum image-plane separation that supported accurate and reliable accommodation. We used an analysis of retinal-image formation to predict when responses might be inaccurate. Accommodation to depth-filtered images was accurate and precise for image-plane separations up to ∼1 diopter, suggesting that depth filtering can be used to precisely match accommodation and vergence demands in a practical display. At larger plane separations, responses broke down in a manner consistent with our analysis. We develop this approach to consider how different spatial frequencies contribute to accommodation control. The results suggest that higher spatial frequencies contribute less to the accommodation response than has previously been thought.


Subject(s)
Accommodation, Ocular/physiology , Depth Perception/physiology , Fixation, Ocular/physiology , Vision, Binocular/physiology , Adolescent , Adult , Asthenopia/physiopathology , Humans , Reference Values , Young Adult
16.
J Vis ; 10(5): 13, 2010 May 01.
Article in English | MEDLINE | ID: mdl-20616139

ABSTRACT

Focus information-blur and accommodation-is highly correlated with depth in natural viewing. We examined the use of focus information in solving the binocular correspondence problem and in interpreting monocular occlusions. We presented transparent scenes consisting of two planes. Observers judged the slant of the farther plane, which was seen through the nearer plane. To do this, they had to solve the correspondence problem. In one condition, the two planes were presented with sharp rendering on one image plane, as is done in conventional stereo displays. In another condition, the planes were presented on two image planes at different focal distances, simulating focus information in natural viewing. Depth discrimination performance improved significantly when focus information was correct, which shows that the visual system utilizes the information contained in depth-of-field blur in solving binocular correspondence. In a second experiment, we presented images in which one eye could see texture behind an occluder that the other eye could not see. When the occluder's texture was sharp along with the occluded texture, binocular rivalry was prominent. When the occluded and occluding textures were presented with different blurs, rivalry was significantly reduced. This shows that blur aids the interpretation of scene layout near monocular occlusions.


Subject(s)
Accommodation, Ocular/physiology , Depth Perception/physiology , Pattern Recognition, Visual/physiology , Vision Disparity/physiology , Vision, Binocular/physiology , Adult , Cues , Humans , Models, Psychological , Perceptual Masking/physiology
17.
Opt Express ; 17(18): 15716-25, 2009 Aug 31.
Article in English | MEDLINE | ID: mdl-19724571

ABSTRACT

Stereoscopic displays present different images to the two eyes and thereby create a compelling three-dimensional (3D) sensation. They are being developed for numerous applications including cinema, television, virtual prototyping, and medical imaging. However, stereoscopic displays cause perceptual distortions, performance decrements, and visual fatigue. These problems occur because some of the presented depth cues (i.e., perspective and binocular disparity) specify the intended 3D scene while focus cues (blur and accommodation) specify the fixed distance of the display itself. We have developed a stereoscopic display that circumvents these problems. It consists of a fast switchable lens synchronized to the display such that focus cues are nearly correct. The system has great potential for both basic vision research and display applications.

18.
Proc SPIE Int Soc Opt Eng ; 7237: 72370R, 2009.
Article in English | MEDLINE | ID: mdl-21479104

ABSTRACT

In stereo displays, binocular disparity creates a striking impression of depth. However, such displays present focus cues-blur and accommodation-that specify a different depth than disparity, thereby causing a conflict. This conflict causes several problems including misperception of the 3D layout, difficulty fusing binocular images, and visual fatigue. To address these problems, we developed a display that preserves the advantages of conventional stereo displays, while presenting correct or nearly correct focus cues. In our new stereo display each eye views a display through a lens that switches between four focal distances at very high rate. The switches are synchronized to the display, so focal distance and the distance being simulated on the display are consistent or nearly consistent with one another. Focus cues for points in-between the four focal planes are simulated by using a depth-weighted blending technique. We will describe the design of the new display, discuss the retinal images it forms under various conditions, and describe an experiment that illustrates the effectiveness of the display in maximizing visual performance while minimizing visual fatigue.

19.
Inorg Chem ; 47(24): 11984-92, 2008 Dec 15.
Article in English | MEDLINE | ID: mdl-19007159

ABSTRACT

The zinc hydrazonide complexes [ClZn(CH(2)C(Me)=NNMe(2))(py)](2), [ClZn(CH(2)C(t-Bu)=NNMe(2))](2), [Zn(CH(2)C(Me)=NNMe(2))(2)](2), Zn(CH(2)C(i-Pr)=NNMe(2))(2), and Zn(CH(2)C(t-Bu)=NNMe(2))(2) were synthesized by salt metathesis reactions, and the coordination polymer [EtZn(CH(2)C(Me)=NNMe(2))](n) was obtained from the reaction between excess ZnEt(2) and [Zn(CH(2)C(Me)=NNMe(2))(2)](2). Single crystal X-ray crystallography studies revealed that the hydrazonide ligands were bound to zinc as chelating alkyl ligands. The ligand precursor [Li(CH(2)C(i-Pr)=NNMe(2))(THF)](n) was also structurally characterized. In the anion of [Li(CH(2)C(i-Pr)=NNMe(2))(THF)](n), the hydrazonide ligand in [EtZn(CH(2)C(Me)=NNMe(2))](n), and the bridging hydrazonide ligands in [Zn(CH(2)C(Me)=NNMe(2))(2)](2) and [ClZn(CH(2)C(Me)=NNMe(2))(py)](2), there is evidence for three-center charge delocalization. In solution, the dimer [Zn(CH(2)C(Me)=NNMe(2))(2)](2) is in equilibrium with the monomer Zn(CH(2)C(Me)=NNMe(2))(2). The thermodynamic parameters DeltaH degrees = 55.8(2.9) kJ/mol, DeltaS degrees = 144(2) J/mol K, and DeltaG degrees (298K) = 13(2) kJ/mol for the equilibrium were obtained from a variable temperature (1)H NMR study.

20.
J Vis ; 8(3): 33.1-30, 2008 Mar 28.
Article in English | MEDLINE | ID: mdl-18484839

ABSTRACT

Three-dimensional (3D) displays have become important for many applications including vision research, operation of remote devices, medical imaging, surgical training, scientific visualization, virtual prototyping, and more. In many of these applications, it is important for the graphic image to create a faithful impression of the 3D structure of the portrayed object or scene. Unfortunately, 3D displays often yield distortions in perceived 3D structure compared with the percepts of the real scenes the displays depict. A likely cause of such distortions is the fact that computer displays present images on one surface. Thus, focus cues-accommodation and blur in the retinal image-specify the depth of the display rather than the depths in the depicted scene. Additionally, the uncoupling of vergence and accommodation required by 3D displays frequently reduces one's ability to fuse the binocular stimulus and causes discomfort and fatigue for the viewer. We have developed a novel 3D display that presents focus cues that are correct or nearly correct for the depicted scene. We used this display to evaluate the influence of focus cues on perceptual distortions, fusion failures, and fatigue. We show that when focus cues are correct or nearly correct, (1) the time required to identify a stereoscopic stimulus is reduced, (2) stereoacuity in a time-limited task is increased, (3) distortions in perceived depth are reduced, and (4) viewer fatigue and discomfort are reduced. We discuss the implications of this work for vision research and the design and use of displays.


Subject(s)
Accommodation, Ocular/physiology , Asthenopia/etiology , Depth Perception/physiology , Flicker Fusion/physiology , Space Perception/physiology , Vision, Binocular/physiology , Adult , Asthenopia/physiopathology , Computer Terminals , Cues , Humans , Imaging, Three-Dimensional , Photic Stimulation , Reference Values
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