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Abstract The biggest challenge in using CRISPR technologies, which limits their widespread application in medicine, is off-target effects. These effects could, in principle, be minimized by ensuring that CRISPR is activated primarily in the targeted cells, thereby reducing the likelihood of unintended genetic modifications in non-target tissues. Therefore, the development of a light activatable CRISPR approach to dynamically control gene activation in both space and time would be highly beneficial. A drawback is that the overwhelming majority of recently introduced light activatable CRISPR systems require UV or blue light exposure, severely limiting the penetration depth of light in tissue at which CRISPR can be activated, and, in the case of UV light, raising safety concerns. A small number of systems that activate CRISPR using longer wavelengths are hindered by either slow light activation or issues related to toxicity and biocompatibility of the proposed techniques in humans. To address this, we developed a split-Cas9/dCas9 system in which activation is achieved through a near-infrared photocleavable dimerization complex. This photoactivation method can be safely used in humans in vivo, easily adapted to different split-Cas9/dCas9 systems, and enables rapid, spatially precise light activation across various cell types. 

This Letter presents a novel, to the best of our knowledge, method to calibrate multi-focus microscopic structured-light three-dimensional (3D) imaging systems with an electrically adjustable camera focal length. We first leverage the conventional method to calibrate the system with a reference focal lengthf₀. Then we calibrate the system with other discrete focal lengthsf_iby determining virtual features on a reconstructed white plane usingf₀. Finally, we fit the polynomial function model using the discrete calibration results forf_i. Experimental results demonstrate that our proposed method can calibrate the system consistently and accurately. 

This paper presents a calibration method for a microscopic structured light system with an extended depth of field (DOF). We first employed the focal sweep technique to achieve large enough depth measurement range, and then developed a computational framework to alleviate the impact of phase errors caused by the standard off-the-shelf calibration target (black circles with a white background). Specifically, we developed a polynomial interpolation algorithm to correct phase errors near the black circles to obtain more accurate phase maps for projector feature points determination. Experimental results indicate that the proposed method can achieve a measurement accuracy of approximately 1.0 $\mathrm{\mu <\#comment/>}$m for a measurement volume of approximately 2,500 $\mathrm{\mu <\#comment/>}$m (W) × 2,000 $\mathrm{\mu <\#comment/>}$m (H) × 500 $\mathrm{\mu <\#comment/>}$m (D). 

Abstract Bile duct cancer is the second most common primary liver cancer, with most diagnoses occurring in the advanced stages. This leads to a poor survival rate, which means a technique capable of reliably detecting pre-cancer in the bile duct is urgently required. Unfortunately, radiological imaging lacks adequate accuracy for distinguishing dysplastic and benign biliary ducts, while endoscopic techniques, which can directly assess the bile duct lining, often suffer from insufficient sampling. Here, we report an endoscopic optical light scattering technique for clinical evaluation of the malignant potential of the bile duct. This technique employs an ultraminiature spatial gating fiber optic probe compatible with cholangioscopes and endoscopic retrograde cholangiopancreatography (ERCP) catheters. The probe allowed us to investigate the internal cellular composition of the bile duct epithelium with light scattering spectroscopy (LSS) and phenotypic properties of the underlying connective tissue with diffuse reflectance spectroscopy (DRS). In a pilot in vivo double-blind prospective study involving 29 patients undergoing routine ERCP procedures, the technique detected malignant transformation with 97% accuracy, showing that biliary duct pre-cancer can be reliably identified in vivo non-invasively.