A whole-slide foundation model for digital pathology from real-world data.

Digital pathology poses unique computational challenges, as a standard gigapixel slide may comprise tens of thousands of image tiles1-3. Prior models have often resorted to subsampling a small portion of tiles for each slide, thus missing the important slide-level context4. Here we present Prov-GigaPath, a whole-slide pathology foundation model pretrained on 1.3 billion 256 × 256 pathology image tiles in 171,189 whole slides from Providence, a large US health network comprising 28 cancer centres. The slides originated from more than 30,000 patients covering 31 major tissue types. To pretrain Prov-GigaPath, we propose GigaPath, a novel vision transformer architecture for pretraining gigapixel pathology slides. To scale GigaPath for slide-level learning with tens of thousands of image tiles, GigaPath adapts the newly developed LongNet5 method to digital pathology. To evaluate Prov-GigaPath, we construct a digital pathology benchmark comprising 9 cancer subtyping tasks and 17 pathomics tasks, using both Providence and TCGA data6. With large-scale pretraining and ultra-large-context modelling, Prov-GigaPath attains state-of-the-art performance on 25 out of 26 tasks, with significant improvement over the second-best method on 18 tasks. We further demonstrate the potential of Prov-GigaPath on vision-language pretraining for pathology7,8 by incorporating the pathology reports. In sum, Prov-GigaPath is an open-weight foundation model that achieves state-of-the-art performance on various digital pathology tasks, demonstrating the importance of real-world data and whole-slide modelling.

Administration of pharmacological sleep aids prior to, during and following critical illness.

BACKGROUND: Sleep in the intensive care unit (ICU) is frequently disturbed and this may have a detrimental effect on recovery. AIM: To determine the use of pharmacological sleep aids in critically ill patients prior to, during and after ICU admission. METHODS: We conducted a single-centre period prevalence study of all adult patients admitted to a university-associated adult medical-surgical ICU for more than two nights in a 3-month period ending September 2019. The major outcome of interest was the proportion of ICU patients who had a pharmacological sleep aid administered prior to, during and after ICU admission. Associations of selected patient variables with sleep aid prescription in the ICU were summarised both as unadjusted univariable comparisons and as adjusted effect estimates returned by a multivariable logistic regression model. RESULTS: During the study period, 370 patients met all eligibility criteria. A pharmacological sleep aid was identified prior to hospital admission in 34 (9%) patients and in 62 (17%) patients during ICU admission. Of the 340 ICU survivors, 292 remained in the same hospital. Of these, 96 (33%) received a pharmacological sleep aid at least once during their post-ICU general hospital ward stay. Pre-hospital sleep aid use, male sex, longer ICU admission and higher APACHE (Acute Physiology and Chronic Health Evaluation) III scores were associated with sleep aid prescription in the ICU. CONCLUSIONS: Pharmacological sleep aids are administered frequently in the ICU with administration increasing substantially after ICU discharge.

Compact high-quality CdSe-CdS core-shell nanocrystals with narrow emission linewidths and suppressed blinking.

High particle uniformity, high photoluminescence quantum yields, narrow and symmetric emission spectral lineshapes and minimal single-dot emission intermittency (known as blinking) have been recognized as universal requirements for the successful use of colloidal quantum dots in nearly all optical applications. However, synthesizing samples that simultaneously meet all these four criteria has proven challenging. Here, we report the synthesis of such high-quality CdSe-CdS core-shell quantum dots in an optimized process that maintains a slow growth rate of the shell through the use of octanethiol and cadmium oleate as precursors. In contrast with previous observations, single-dot blinking is significantly suppressed with only a relatively thin shell. Furthermore, we demonstrate the elimination of the ensemble luminescence photodarkening that is an intrinsic consequence of quantum dot blinking statistical ageing. Furthermore, the small size and high photoluminescence quantum yields of these novel quantum dots render them superior in vivo imaging agents compared with conventional quantum dots. We anticipate these quantum dots will also result in significant improvement in the performance of quantum dots in other applications such as solid-state lighting and illumination.

Multistage nanoparticle delivery system for deep penetration into tumor tissue.

Current Food and Drug Administration-approved cancer nanotherapeutics, which passively accumulate around leaky regions of the tumor vasculature because of an enhanced permeation and retention (EPR) effect, have provided only modest survival benefits. This suboptimal outcome is likely due to physiological barriers that hinder delivery of the nanotherapeutics throughout the tumor. Many of these nanotherapeutics are ≈ 100 nm in diameter and exhibit enhanced accumulation around the leaky regions of the tumor vasculature, but their large size hinders penetration into the dense collagen matrix. Therefore, we propose a multistage system in which 100-nm nanoparticles "shrink" to 10-nm nanoparticles after they extravasate from leaky regions of the tumor vasculature and are exposed to the tumor microenvironment. The shrunken nanoparticles can more readily diffuse throughout the tumor's interstitial space. This size change is triggered by proteases that are highly expressed in the tumor microenvironment such as MMP-2, which degrade the cores of 100-nm gelatin nanoparticles, releasing smaller 10-nm nanoparticles from their surface. We used quantum dots (QD) as a model system for the 10-nm particles because their fluorescence can be used to demonstrate the validity of our approach. In vitro MMP-2 activation of the multistage nanoparticles revealed that the size change was efficient and effective in the enhancement of diffusive transport. In vivo circulation half-life and intratumoral diffusion measurements indicate that our multistage nanoparticles exhibited both the long circulation half-life necessary for the EPR effect and the deep tumor penetration required for delivery into the tumor's dense collagen matrix.

Impact of focused cardiac and lung ultrasound screening performed by a junior doctor during admission to the surgical ward on patients before emergency non-cardiac surgery: A pilot prospective observational study.

Purpose: To assess whether pre-operative focused cardiac ultrasound and lung ultrasound screening performed by a junior doctor can change diagnosis and clinical management of patients aged ≥65 years undergoing emergency, non-cardiac surgery. Method: This pilot prospective observational study included patients scheduled for emergency, non-cardiac surgery. The treating team completed a diagnosis and management plan before and after focused cardiac and lung ultrasound, which was performed by a junior doctor. Changes to diagnosis and management after ultrasound were recorded. Ultrasound images were assessed for image and diagnostic interpretation by an independent expert. Results: There was a total of 57 patients at age 77 ± 8 years. Cardiopulmonary pathology was suspected after clinical assessment in 28% vs. 72% after ultrasound (including abnormal haemodynamic state in 61%, valvular lesions in 32%, acute pulmonary oedema/interstitial syndrome in 9% and bilateral pleural effusions in 2%). In 67% of patients, the perioperative management was changed. The changes were in fluid therapy in 30%, cardiology consultation in 7%, formal in- or out-patient, transthoracic echocardiography in 11% and 30% respectively. Discussion: The impact of pre-operative focused cardiac and lung ultrasound on diagnosis and management of patients on the hospital ward before emergency non-cardiac surgery by a junior doctor was comparable to previous studies of anaesthetists experienced in focused ultrasound. However, the ability to recognise when image quality is insufficient for diagnosis is an important consideration for novice sonographers. Conclusions: Focused cardiac and lung ultrasound examination by a junior doctor is feasible and may change preoperative diagnosis and management in patients of 65 years or older, admitted for emergency non-cardiac surgery.

Compact biocompatible quantum dots via RAFT-mediated synthesis of imidazole-based random copolymer ligand.

We present a new class of polymeric ligands for quantum dot (QD) water solubilization to yield biocompatible and derivatizable QDs with compact size (approximately 10-12 nm diameter), high quantum yields (>50%), excellent stability across a large pH range (pH 5-10.5), and low nonspecific binding. To address the fundamental problem of thiol instability in traditional ligand exchange systems, the polymers here employ a stable multidentate imidazole binding motif to the QD surface. The polymers are synthesized via reversible addition-fragmentation chain transfer-mediated polymerization to produce molecular weight controlled monodisperse random copolymers from three types of monomers that feature imidazole groups for QD binding, polyethylene glycol (PEG) groups for water solubilization, and either primary amines or biotin groups for derivatization. The polymer architecture can be tuned by the monomer ratios to yield aqueous QDs with targeted surface functionalities. By incorporating amino-PEG monomers, we demonstrate covalent conjugation of a dye to form a highly efficient QD-dye energy transfer pair as well as covalent conjugation to streptavidin for high-affinity single molecule imaging of biotinylated receptors on live cells with minimal nonspecific binding. The small size and low serum binding of these polymer-coated QDs also allow us to demonstrate their utility for in vivo imaging of the tumor microenvironment in live mice.

A Retrospective Review Comparing the Safety and Efficacy of 120 Versus 160 Applications of Selective Laser Trabeculoplasty.

PURPOSE: To compare the effectiveness and safety of 120 applications versus 160 applications of selective laser trabeculoplasty (SLT) at reducing intraocular pressure (IOP) from baseline in glaucoma patients over a 1-year period. METHODS: A retrospective chart review was conducted, comprising 376 eyes from 199 patients who underwent SLT treatment performed by the same glaucoma subspecialist from 2014 to 2015. Data were obtained on patients' clinical features, management, and outcomes. Patients were treated with either 120 applications or 160 applications of SLT per 360 degrees of trabecular meshwork over 2 sessions. Statistical analyses were performed comparing baseline IOP with IOP at 6 weeks and 1-year follow-up after completion of treatment. The incidence and severity of transient IOP rises immediately post-SLT was also recorded. RESULTS: Both SLT regimes were effective at reducing IOP. Univariate t tests showed that the 160 applications group had significantly greater mean reduction of IOP from baseline at both 6 weeks (4.6 vs. 3.6 mm Hg, P=0.015) and 1-year time points (4.1 vs. 2.8 mm Hg, P=0.019). However, when multivariate analyses were used to account for the effects of clustering and include other covariates such as age, baseline IOP, history of previous SLT there was no significant difference between success rates of the 2 treatment groups at either time points. Higher baseline IOP was associated with greater IOP reduction at 6 weeks (P<0.001) and 1 year (P<0.001) for both treatment groups. There was no statistical difference in incidence and severity of IOP spikes at 1-hour post-SLT between the 2 treatment groups. CONCLUSIONS: SLT produces a significant IOP-lowering effect and treatment with 160 applications per 360 degrees may be more effective than 120 applications per 360 degrees. Furthermore, 160 applications of SLT does not increase the risk of transient IOP spikes.

Avidin as a model for charge driven transport into cartilage and drug delivery for treating early stage post-traumatic osteoarthritis.

Local drug delivery into cartilage remains a challenge due to its dense extracellular matrix of negatively charged proteoglycans enmeshed within a collagen fibril network. The high negative fixed charge density of cartilage offers the unique opportunity to utilize electrostatic interactions to augment transport, binding and retention of drug carriers. With the goal of developing particle-based drug delivery mechanisms for treating post-traumatic osteoarthritis, our objectives were, first, to determine the size range of a variety of solutes that could penetrate and diffuse through normal cartilage and enzymatically treated cartilage to mimic early stages of OA, and second, to investigate the effects of electrostatic interactions on particle partitioning, uptake and binding within cartilage using the highly positively charged protein, Avidin, as a model. Results showed that solutes having a hydrodynamic diameter ≤10 nm can penetrate into the full thickness of cartilage explants while larger sized solutes were trapped in the tissue's superficial zone. Avidin had a 400-fold higher uptake than its neutral same-sized counterpart, NeutrAvidin, and >90% of the absorbed Avidin remained within cartilage explants for at least 15 days. We report reversible, weak binding (K(D) ~ 150 µM) of Avidin to intratissue sites in cartilage. The large effective binding site density (N(T) ~ 2920 µM) within cartilage matrix facilitates Avidin's retention, making its structure suitable for particle based drug delivery into cartilage.

Multistage nanoparticles for improved delivery into tumor tissue.

The enhanced permeability and retention (EPR) effect has been a key rationale for the development of nanoscale carriers to solid tumors. As a consequence of EPR, nanotherapeutics are expected to improve drug and detection probe delivery, have less adverse effects than conventional chemotherapy, and thus result in improved detection and treatment of tumors. Physiological barriers posed by the abnormal tumor microenvironment, however, can hinder the homogeneous delivery of nanomedicine in amounts sufficient to eradicate cancer. To effectively enhance the therapeutic outcome of cancer patients by nanotherapeutics, we have to find ways to overcome these barriers. One possibility is to exploit the abnormal tumor microenvironment for selective and improved delivery of therapeutic agents to tumors. Recently, we proposed a multistage nanoparticle delivery system as a potential means to enable uniform delivery throughout the tumor and improve the efficacy of anticancer therapy. Here, we describe the synthesis of a novel multistage nanoparticle formulation that shrinks in size once it enters the tumor interstitial space to optimize the delivery to tumors as well as within tumors. Finally, we provide detailed experimental methods for the characterization of such nanoparticles.

Control of the carrier type in InAs nanocrystal films by predeposition incorporation of Cd.

Nanocrystal (NC) films have been proposed as an alternative to bulk semiconductors for electronic applications such as solar cells and photodetectors. One outstanding challenge in NC electronics is to robustly control the carrier type to create stable p-n homojunction-based devices. We demonstrate that the postsynthetic addition of Cd to InAs nanocrystals switches the resulting InAs:Cd NC films from n-type to p-type when operating in a field effect transistor. This method presents a stable, facile way to control the carrier type of InAs nanocrystals prior to deposition. We present two mechanisms to explain the observed switch in carrier type. In mechanism 1, Cd atoms are incorporated at In sites in the lattice and act as acceptor defects, forming a partially compensated p-type semiconductor. In mechanism 2, Cd atoms passivate donor-type InAs surface states and create acceptor-type surface states. This work represents a critical step toward the creation of p-n homojunction-based NC electronics.