Fluorescent Nanoparticle Uptake by Myzocytosis and Endocytosis in Colpodella sp. ATCC 50594.

Colpodella sp. (ATCC 50594) is a free-living biflagellate predator closely related to pathogenic Apicomplexa such as Plasmodium, Cryptosporidium and Toxoplasma gondii. Colpodella sp. (ATCC 50594) obtain nutrients by preying on Parabodo caudatus using myzocytosis. The organization of the myzocytic apparatus and the mechanism of nutrient uptake into the posterior food vacuole of Colpodella species is unknown. In this study, we investigated myzocytosis using light and transmission electron microscopy. We investigated the uptake of 40 nm and 100 nm fluorescent nanoparticles and E. coli BioParticles by Colpodella sp. (ATCC 50594) in a diprotist culture. Transmission electron microscopy was used to investigate the morphology of the tubular tether formed during myzocytosis. E. coli BioParticles were taken up by P. caudatus but not by Colpodella sp. (ATCC 50594). Both protists took up the 100 nm and 40 nm beads, which were observed distributed in the cytoplasm of free unattached Colpodella sp. (ATCC 50594) trophozoites, and also in feeding Colpodella sp. (ATCC 50594) trophozoites and in the pre-cysts. Fragments of the nucleus and kinetoplast of P. caudatus and the nanoparticles were identified in the tubular tether being aspirated into the posterior food vacuole of Colpodella sp. (ATCC 50594). Unattached Colpodella sp. (ATCC 50594) endocytose nutrients from the culture medium independently from myzocytosis. The mechanisms of myzocytosis and endocytosis among Colpodella species may provide important insights into nutrient uptake among the pathogenic apicomplexans.

Intraband Transition of HgTe Nanocrystals for Long-Wave Infrared Detection at 12 µm.

The synthesis of n-doped HgTe colloidal quantum dots was optimized to produce samples with a 1Se-1Pe intraband transition in the long-wave infrared (8-12 µm). The spin-orbit splitting of 1Pe states places the 1Se-1Pe1/2 transition around 10 µm. The narrow line width of 130 cm-1 at 300 K is limited by the size distribution. This narrowing leads to an absorption coefficient about 5 times stronger than is possible with the HgTe CQD interband transition at similar energies. From 300 to 80 K, the intraband transition blueshifts by 90 cm-1, while the interband transition redshifts by 350 cm-1. These shifts are assigned to the temperature dependence of the band structure. With ∼2 electrons/dot doping at 80 K, a photoconductive film of 80 nm thickness on a quarter wave reflector substrate showed a detectivity (D*) of ∼107 Jones at 500 Hz in the 8-12 µm range.

Room-Temperature 15% Efficient Mid-Infrared HgTe Colloidal Quantum Dot Photodiodes.

Mid-infrared HgTe colloidal quantum dot photovoltaic devices previously achieved background-limited infrared photodetection at cryogenic temperatures but also decreased from 20 to 1% efficiency from 150 to 300 K. The reduced quantum efficiency was tentatively attributed to the carrier diffusion length being much shorter than the device thickness of ∼400 nm at room temperature. Here, the carrier diffusion length is measured and is found to peak at 215 nm at 200 K and decrease only to 180 nm at 295 K. It is therefore not the cause of the much larger reduced quantum efficiency. Instead, it is shown that the efficiency drops due to the series resistance. With the device size reduced to 50 by 50 µm, the room-temperature quantum efficiency reaches 10 and 15% for HgTe colloidal quantum dot devices with 2400 cm-1 (4.2 µm) and 2675 cm-1 (3.7 µm) cutoff, respectively. These small-area devices achieve background-limited photodetection at 150 K and a detectivity above 109 Jones at room temperature with a cutoff at 2675 cm-1 (3.7 µm).

Utility of Abbreviated Small Bowel Follow Through Study in the Management of Small Bowel Obstruction.

INTRODUCTION: Small bowel obstruction is a common surgical complaint. Most small bowel obstructions are managed successfully nonoperatively. Unanimous guidelines for nonoperative management of small bowel obstruction do not exist. METHODS: A standardized protocol for water-soluble contrast administration and abbreviated small bowel follow through imaging was implemented in January of 2021. A retrospective chart review identified 111 patients admitted for SBO from 6/2019 to 9/2019 for a control group. A planned follow-up review identified 158 patients managed according to the new protocol from 3/2021 to 10/2021. The primary outcome was in-hospital length of stay. Standard statistical analyses were performed and pre-specified. RESULTS: Before implementation of the standardized protocol patients that were managed strictly nonoperatively, the mean length of stay (LOS) was 8.3 days. After implementation, the average LOS was 4.8 (P < .0001). Comparatively, patients admitted after protocol implementation were more likely to undergo CT scan with PO contrast on admission (98.1% vs 90.1%; P < .005), undergo NG tube decompression (84.7% vs 68.5%; P < .005), and undergo water-soluble contrast with abbreviated or formal SBFT (75.3% vs 37.8%; P < .0001). CONCLUSION: Implementation of a standardized protocol utilizing abbreviated SBFT with water-soluble contrast for the management of SBO at our institution resulted in a decrease in the average length of stay for patients definitively managed in a nonoperative fashion.

International medical tourism of US cancer patients for alternative cancer treatments: Financial, demographic, and clinical profiles of online crowdfunding campaigns.

BACKGROUND: Previous research has found that individuals may travel outside their home countries in pursuit of alternative cancer therapies (ACT). The goal of this study is to compare individuals in the United States who propose plans for travel abroad for ACT, compared with individuals who seek ACT domestically. METHODS: Clinical and treatment data were extracted from campaign descriptions of 615 GoFundMe® campaigns fundraising for individuals in the United States seeking ACT between 2011 and 2019. We examined treatment modalities, treatment location, fundraising metrics, and online engagement within campaign profiles. Clinical and demographic differences between those who proposed international travel and those who sought ACT domestically were examined using two-sided Fisher's exact tests. Differences in financial and social engagement data were examined using two-sided Mann-Whitney tests. RESULTS: Of the total 615 campaigns, 237 (38.5%) mentioned plans to travel internationally for ACT, with the majority (81.9%) pursuing travel to Mexico. Campaigns that proposed international treatment requested more money ($35,000 vs. $22,650, p < 0.001), raised more money ($7833 vs. $5035, p < 0.001), had more donors (57 vs. 45, p = 0.02), and were shared more times (377 vs. 290.5, p = 0.008) compared to campaigns that did not. The median financial shortfall was greater for campaigns pursuing treatments internationally (-$22,640 vs. -$13,436, p < 0.003). CONCLUSIONS: Campaigns proposing international travel for ACT requested and received more money, were shared more online, and had more donors. However, there was significantly more unmet financial need among this group, highlighting potential financial toxicity on patients and families.

Growth in eligibility criteria content and failure to accrue among National Cancer Institute (NCI)-affiliated clinical trials.

BACKGROUND: Cancer trial accrual is a national priority, yet up to 20% of trials fail to accrue. Trial eligibility criteria growth may be associated with accrual failure. We sought to quantify eligibility criteria growth within National Cancer Institute (NCI)-affiliated trials and determine impact on accrual. METHODS: Utilizing the Aggregated Analysis of ClinicalTrials.gov, we analyzed phase II/III interventional NCI-affiliated trials initiated between 2008 and 2018. Eligibility criteria growth was assessed via number of unique content words within combined inclusion and exclusion criteria. Association between unique word count and accrual failure was evaluated with multivariable logistic regression, adjusting for known predictors of failure. Medical terms associated with accrual failure were identified via natural language processing and categorized. RESULTS: Of 1197 trials, 231 (19.3%) failed due to low accrual. Accrual failure rate increased with eligibility criteria growth, from 11.8% in the lowest decile (12-112 words) to 29.4% in the highest decile (445-750 words). Median eligibility criteria increased over time, from 214 (IQR [23, 282]) unique content words in 2008 to 417 (IQR [289, 514]) in 2018 (r2  = 0.73, P < 0.001). Eligibility criteria growth was independently associated with accrual failure (OR: 1.09 per decile, 95% CI [1.03-1.15], p = 0.004). Eighteen exclusion criteria categories were significantly associated with accrual failure, including renal, pulmonary, and diabetic, among others (Bonferroni-corrected p < 0.001). CONCLUSIONS: Eligibility criteria content growth is increasing dramatically among NCI-affiliated trials and is strongly associated with accrual failure. These findings support national initiatives to simplify eligibility criteria and suggest that further efforts are warranted to improve cancer trial accrual.

A 0.43 g Wireless Battery-Less Neural Recorder With On-Chip Microelectrode Array and Integrated Flexible Antenna.

This work presents a single-chip battery-less neural recorder with 12 on-die microelectrodes. It can be powered wirelessly up to 16 cm away from a horn antenna at 915 MHz and only consumes 104 µW dc power for accessing 10 enabled recording sites simultaneously, transmitting at 5 Mbps. The implantable device integrated with a flexible antenna weighs only 0.43 gram. In vivo measurements on an unrestricted mouse have been successfully conducted, showing response to visual stimuli.

Novel life cycle stages of Colpodella sp. (Apicomplexa) identified using Sam-Yellowe’s trichrome stains and confocal and electron microscopy / Nuevas etapas del ciclo de vida de Colpodella sp. (Apicomplexa) identificado mediante tinciones tricrómicas de Sam-Yellowe y microscopía confocal y electrónica

Colpodella spp. are free-living flagellates closely related to the apicomplexans. Human infections by Colpodella sp. have been reported. A biflagellated trophozoite and cyst stage comprise the known life cycle stages of Colpodella sp. However, the process of encystation and excystation within the life cycle is unclear. Life cycle stages initiating human infections are unknown. We performed a detailed investigation of the life cycle of Colpodella sp. (ATCC 50594) in culture using Sam-Yellowe’s trichrome stains and differential interference contrast (DIC) for light microscopy and fluorescence microscopy of Congo red-stained cells and investigated ultrastructure using transmission electron microscopy (TEM). We report previously undocumented stages of Colpodella sp. Asymmetric and asynchronous division was detected inside cysts by trichrome staining and by TEM. Odd-numbered juveniles and cysts containing more than four juvenile trophozoites were identified. Live imaging of active cultures captured the excystation and egress of juvenile trophozoites and confirmed the presence of multinucleate cysts. The ultrastructure of the multinucleate cyst is reminiscent of apicomplexan schizonts. Insights gained from the life cycle stages observed in culture allowed the construction of the life cycle of Colpodella sp. Knowledge of the life cycle will aid biochemical and molecular characterization of Colpodella sp. and help identify stages in human infections.(AU)

Enzymatic Laser-Induced Graphene Biosensor for Electrochemical Sensing of the Herbicide Glyphosate.

Glyphosate is a globally applied herbicide yet it has been relatively undetectable in-field samples outside of gold-standard techniques. Its presumed nontoxicity toward humans has been contested by the International Agency for Research on Cancer, while it has been detected in farmers' urine, surface waters and crop residues. Rapid, on-site detection of glyphosate is hindered by lack of field-deployable and easy-to-use sensors that circumvent sample transportation to limited laboratories that possess the equipment needed for detection. Herein, the flavoenzyme, glycine oxidase, immobilized on platinum-decorated laser-induced graphene (LIG) is used for selective detection of glyphosate as it is a substrate for GlyOx. The LIG platform provides a scaffold for enzyme attachment while maintaining the electronic and surface properties of graphene. The sensor exhibits a linear range of 10-260 µ m, detection limit of 3.03 µ m, and sensitivity of 0.991 nA µ m -1. The sensor shows minimal interference from the commonly used herbicides and insecticides: atrazine, 2,4-dichlorophenoxyacetic acid, dicamba, parathion-methyl, paraoxon-methyl, malathion, chlorpyrifos, thiamethoxam, clothianidin, and imidacloprid. Sensor function is further tested in complex river water and crop residue fluids, which validate this platform as a scalable, direct-write, and selective method of glyphosate detection for herbicide mapping and food analysis.

Delineating the Subarachnoid Space in the Adult Lumbosacral Spine Using Computed Tomographic Myelography: An Aid for Clinical Target Volume Delineation in Craniospinal Irradiation.

Purpose: Our aim was to characterize the patterns of cerebrospinal fluid (CSF) extension in the lumbosacral spine using computed tomography (CT) myelograms to provide an evidence base for clinical target volume (CTV) definition in adults receiving craniospinal irradiation. Methods and Materials: This was a retrospective analysis of diagnostic CT lumbar myelograms performed in 30 patients between the ages of 22 and 50. Lateral extension of CSF beyond the thecal sac was measured along each lumbar and sacral nerve root to the nearest millimeter, as was the distance of inferior extension of CSF beyond the caudal end of the thecal sac. Each patient's lateral and inferior CSF extensions were mapped onto a standardized CT data set to create a model target volume in the lumbosacral spine that would contain the aggregate observed CSF distributions from the analyzed CT myelograms. The median extension distances, interquartile ranges, and 90th percentile for distance at each level were calculated. Results: The median lateral extension of CSF along nerve roots beyond the thecal sac-as measured perpendicular to the longitudinal axis-increased from 0 mm (interquartile range [IQR], 0-4 mm) at L1 to 8 mm (IQR, 6-12 mm) at S1 and 0 mm (IQR, 0-0 mm) at S4. The 90th percentile ranged from 5 to 14 mm laterally, with a pattern partially extending into the S1 and S2 sacral foramen. Median CSF extension inferior to the caudal sac was 5 mm (IQR, 2-8 mm), with 90% of patients within 12 mm. An atlas was generated to guide CTV delineation for highly conformal radiation techniques. Conclusion: These results provide information on patterns of CSF extension in the lumbosacral spine of adults and can serve as a model for CTV guidelines that balance comprehensive coverage of the CSF compartment while minimizing the dose to nontarget tissues.

The Clinical Significance of Maximum Tumor Diameter on MRI in Men Undergoing Radical Prostatectomy or Definitive Radiotherapy for Locoregional Prostate Cancer.

INTRODUCTION: Maximum tumor diameter (MTD) on pretreatment magnetic resonance imaging (MRI) has the potential to further risk stratify for men with prostate cancer (PCa) prior to definitive local therapy. We aim to evaluate the prognostic impact of radiographic maximum tumor diameter (MTD) in men with localized prostate cancer. PATIENTS AND METHODS: From a single-center retrospective cohort of men receiving definitive treatment for PCa (radical prostatectomy [RP] or radiotherapy [RT]) with available pretreatment MRI, we conducted univariable and multivariable Cox proportional-hazards models for progression using clinical variables including age, NCCN risk group, radiographic extracapsular extension (ECE), radiographic seminal vesical invasion (SVI), and MTD. RP and RT cohorts were analyzed separately. Covariates were used in a classification and regression tree (CART) analysis and progression-free survival was estimated with the Kaplan-Meier method and groups were compared using log-rank tests. RESULTS: The cohort included 631 patients (n = 428 RP, n = 203 RT). CART analysis identified 4 prognostic groups for patients treated with RP and 2 prognostic groups in those treated with RT. In the RP cohort, NCCN low/intermediate risk group patients with MTD>=15 mm had significantly worse PFS than those with MTD <= 14 mm, and NCCN high-risk patients with radiographic ECE had significantly worse PFS than those without ECE. In the RT cohort, PFS was significantly worse in the cohort with MTD >= 23 mm than those <= 22 mm. CONCLUSION: Radiographic MTD may be a useful prognostic factor for patients with locoregional prostate cancer. This is the first study to illustrate that the importance of pretreatment tumor size may vary based on treatment modality.

Measurement of Phacoemulsification Vacuum Pressure in the Oertli CataRhex3.

Purpose: To determine the actual vacuum pressure generated by the Oertli CataRhex 3® (Oertli), using an external measuring system. Methods: The effective vacuum pressure created by the Oertli was measured with a pressure device that was continuous with the vacuum tubing system while closed to the external environment. Measurements were taken with the machine set to 300 and 500 mmHg at flow rates of 20, 35, and 50 mL/min and at bottle heights of 60, 80, and 100 cm. Pressures were recorded after the foot pedal was depressed to vacuum setting (second position), and the pressure was allowed to stabilize. Subsequently, it was compared to the pressure value displayed by the machine. Results: Externally measured vacuum pressure was on average 13.02% greater (39.05 mmHg) than displayed vacuum pressure at 300 mmHg (P < 0.005) and 8.60% greater (42.98 mmHg) than displayed vacuum at 500 mmHg (P < 0.005). The average difference between displayed and measured pressure increased with increasing bottle heights. Conclusion: On average, the vacuum pressure generated in the Oertli was found to be significantly higher than the machine's reading when the machine was set at 300 mmHg and 500 mmHg. Adjusting vacuum had variable effects on the measured versus displayed pressure readings.

Timing and Motivations for Alternative Cancer Therapy With Insights From a Crowdfunding Platform: Cross-sectional Mixed Methods Study.

BACKGROUND: Alternative cancer therapy is associated with increased mortality, but little is known about those who pursue it. OBJECTIVE: We aimed to describe individuals' motivations for using alternative cancer therapies and determine whether motivations differ based on individuals' timing of seeking alternative therapies. METHODS: We used data from 649 campaigns posted on the website GoFundMe between 2011 and 2019 for beneficiaries with cancer pursuing alternative therapy. The data were analyzed using a mixed methods approach. Campaigns were categorized by timing of alternative therapy (either before or after experiencing conventional therapy). Qualitative analysis identified motivational themes. Chi-square tests of independence and Fisher tests (all 2-sided) determined significant differences in the presence of motivational themes between groups. RESULTS: The expression of concerns about the efficacy of conventional therapy was significantly more likely in campaigns for individuals who used conventional therapy first than in campaigns for individuals who started with alternative therapy (63.3% vs 41.7%; P<.001). Moreover, on comparing those who started with alternative therapy and those who switched from conventional to alternative therapy, those who started with alternative therapy more often expressed natural and holistic values (49.3% vs 27.0%; P<.001), expressed an unorthodox understanding of cancer (25.5% vs 16.4%; P=.004), referenced religious or spiritual beliefs (15.1% vs 8.9%; P=.01), perceived alternative treatment as efficacious (19.1% vs 10.2%; P=.001), and distrusted pharmaceutical companies (3.2% vs 0.5%; P=.04). CONCLUSIONS: Individuals sought treatments that reflected their values and beliefs, even if scientifically unfounded. Many individuals who reported prior conventional cancer therapy were motivated to pursue alternative treatments because they perceived the conventional treatments to be ineffective.

Accommodative movements of the choroid in the optic nerve head region of human eyes, and their relationship to the lens.

The ciliary muscle (CM) powers the accommodative response, and during accommodation the CM pulls the choroid forward in the region of the ora serrata. Our goal was to elucidate the accommodative movements of the choroid in the optic nerve region in humans and to determine whether these movements are related to changes in the lens dimensions that occur with aging, in the unaccommodated and accommodated state. Both eyes of 12 human subjects (aged 18-51 yrs) were studied. Homatropine (1 drop/5%) was used to relax the ciliary muscle (unaccommodated or "resting" eye) and pilocarpine was used to induce the maximum accommodative response (2 drops/4%) (accommodated eye). Images of the fundus and choroid were collected in the region of the optic nerve (ON) via Spectralis OCT (infrared and EDI mode), and choroidal thickness was determined. Ultrasound biomicroscopy (UBM; 50 MHz, 35 MHz) images were collected in the region of the lens/capsule and ciliary body. OCT and UBM images were collected in the resting and accommodated state. The unaccommodated choroidal thickness declined significantly with age (p = 0.0073, r = 0.73) over the entire age range of the subjects studied (18-51 years old). The choroidal thickness was significantly negatively correlated with lens thickness in the accommodated (p = 0.01) and the unaccommodated states (p = 0.005); the thicker the lens the thinner the choroid. Choroid movements around the optic nerve during accommodation were statistically significant; during accommodation the choroid both thinned and moved centrifugally (outward/away from the optic nerve head). The accommodative choroid movements did not decline significantly with age and were not correlated with accommodative amplitude. Measurement of the choroidal thickness is possible with the Spectralis OCT instrument using EDI mode and can be used to determine the accommodative changes in choroidal thickness. The choroidal thickness decreased with age and during accommodation. It may be that age-related choroidal thinning is due to changes in the geometry of the accommodative apparatus to which it is attached (i.e., ciliary muscle/lens complex) such that when the lens is thicker, the choroid is thinner. Accommodative decrease in choroidal thickness and stretch of the retina/choroid may indicate stress/strain forces in the region of the optic nerve during accommodation and may have implications for glaucoma.

Adult Mesenchymal Stem Cells and Derivatives in Improved Elastin Homeostasis in a Rat Model of Abdominal Aortic Aneurysms.

Abdominal aortic aneurysms (AAAs) are localized rupture-prone expansions of the aorta with limited reversibility that develop due to proteolysis of the elastic matrix. Natural regenerative repair of an elastic matrix is difficult due to the intrinsically poor elastogenicity of adult vascular smooth muscle cells (VSMCs). This justifies the need to provide external, pro-elastin regenerative- and anti-proteolytic stimuli to VSMCs in the AAA wall towards reinstating matrix structure in the aorta wall. Introducing alternative phenotypes of highly elastogenic and contractile cells into the AAA wall capable of providing such cues, proffers attractive prospects for AAA treatment. In this regard, we have previously demonstrated the superior elastogenicity of bone marrow mesenchymal stem cell (BM-MSC)-derived SMCs (cBM-SMCs) and their ability to provide pro-elastogenic and anti-proteolytic stimuli to aneurysmal SMCs in vitro. However, the major issues associated with cell therapy, such as their natural ability to home into the AAA tissue, their in vivo biodistribution and retention in the AAA wall, and possible paracrine effects on AAA tissue repair processes in the event of localization in remote tissues remain uncertain. Therefore, in this study we focused on assessing the fate, safety, and AAA reparative effects of BM-MSC-derived cBM-SMCs in vivo. Our results indicate that the cBM-SMCs (a) possess natural homing abilities similar to the undifferentiated BM-MSCs, (b) exhibit higher retention upon localization in the aneurysmal aorta than BM-MSCs, (c) downregulate the expression of several inflammatory and pro-apoptotic cytokines that are upregulated in the AAA wall contributing to accelerated elastic matrix breakdown and suppression of elastic fiber neo-assembly, repair, and crosslinking, and (d) improve elastic matrix content and structure in the AAA wall toward slowing the growth of AAAs. Our study provides initial evidence of the in vivo elastic matrix reparative benefits of cBM-SMCs and their utility in cell therapy to reverse the pathophysiology of AAAs.

Ultrastructure of Myzocytosis and Cyst Formation, and the Role of Actin in Tubular Tether Formation in Colpodella sp. (ATCC 50594).

Free-living relatives of the Apicomplexa such as Colpodella species, Alphamonas species, and Voromonas pontica are predators that prey on ciliate, bodonid, and algal prey using the process of myzocytosis. During myzocytosis, the pseudoconoid is used to attach to the prey leading to aspiration of cytoplasmic contents of the prey into a posterior food vacuole formed in the predator, aided by secretions from the apical complex organelles. The conoid and associated proteins are conserved among the apicomplexa. However, the organization and function of the pseudoconoid during myzocytosis are not well understood. In this study, we investigated the morphology and ultrastructure of Colpodella sp. (ATCC 50594) during the stages of myzocytosis and cyst formation in the life cycle using light microscopy and transmission electron microscopy (TEM) in order to identify the organization of the tubular tether involved in nutrient aspiration by Colpodella sp. Tubular tethers of varying lengths were identified by light microscopy. We report that initial contact by Colpodella sp. trophozoites with Parabodo caudatus prey is by an area posterior to the apical tip of the rostrum that engulfs the membrane of the prey pulling it into the cytoplasm of the predator. The tubular tether that forms contains membranes of both predator and prey and is facilitated by microtubule organization and the cytoskeleton at the point of contact. Cytochalasin D treatment of diprotist cultures resulted in morphological distortions of trophozoites and the tubular tether suggesting a role of actin in the formation of the tubular tether. This mechanism of predation may provide insight into the mode of invasion observed in pathogenic apicomplexan zoites during host cell entry.

Optimization of Phacoemulsification Tip Gauge on the Oertli CataRhex3 in an in vitro Setting.

Purpose: To evaluate the effect of each of the tip sizes available for the Oertli CataRhex3® phacoemulsification machine on efficiency. Methods: Porcine lenses were fixed in formalin for 2 hours, then cut into 3.0 mm cubes. We studied three Oertli tips, all of which had a 30-degree bevel: easyTip 2.2 mm (20G), easyTip 2.8 mm (19G), and CO-MICS (21G). For the 19G and 20G tips, vacuum was set at 600 mmHg, irrigation rate at 50 mL/min, continuous power 70%, and bottle height 85 cm. For the 21G tip, vacuum was set at 450 mmHg; irrigation and power settings were identical to those used for the easyTip tips. We measured time to removal and chatter events to determine efficiency. Results: Results from 20 trials for each tip showed that the larger the gauge size, the more quickly lens fragments were removed. Chatter events demonstrated an increasing trend with smaller tip gauge. The 19G tip used an average time to fragment removal of 2.8 seconds; the 20G, 3.2 seconds; and the 21G, 4.6 seconds. Increasing tip diameter from 21G to 20G decreased emulsification time by 33% (P = 0.02). Increasing the diameter from 21G to 19G further decreased time to emulsification by 42% (P = 0.003). The 21G tip had a mean 1.4 events/cube; 20G, 0.35 events; and 19G, 0.1 events. Differences in mean chatter events for each tip were each statistically significant. Conclusion: These data suggest that when evaluated by chatter events and emulsification time, the 2.8 mm (19G) easyTip proves to have greatest efficiency.

Mid-infrared HgTe Colloidal Quantum Dot LEDs.

Mid-infrared HgTe colloidal quantum dot electroluminescent devices are demonstrated. With emission at 4 µm, devices achieved an external quantum efficiency of ∼10-3 and power conversion efficiency of ∼10-4 under biases of a few volts. The power conversion efficiency benefited from lowering the transparent electrode resistance through the incorporation of a metal conductive grid. The average power emitted was about 16 µW at 2 V bias with 50% duty cycle and a 1 mm2 device. The room-temperature electroluminescence efficiency at low current was limited by the photoluminescence efficiency of the quantum dots, while the diode structure provided efficient electron-hole recombination.