Single-photon Avalanche Diodes in sub-100nm Standard CMOS Technologies

Single-photon avalanche diodes (SPADs) are evaluated in two sub-100nm CMOS technologies. Several geometries are implemented, whereas premature edge breakdown (PEB) prevention is achieved with n-well rings. The octagonal SPADs are implemented in 90nm and 65nm standard CMOS technologies. Full characterization of SPAD performance is carried out as a function of bias and temperature. To the best of our knowledge, this is the first report of SPAD in any 65nm CMOS technology

A consecutive series of 235 epigastric hernias

Abstract Background Epigastric herniation is a common, though not always symptomatic condition. It is likely, that in accordance to the tension-free principles for other hernias, epigastric hernia repair should be mesh based. Methods Patients from two large hospitals were investigated retrospectively if they were operated on an epigastric hernia for the past 6 years. Follow-up was completed with a postal questionnaire. Results A total of 235 patients (50 % male) were operated. Sixty-eight patients were operated with mesh and 167 patients with suture repair. Forty-six patients were loss-to follow-up (19.6 %). In the mesh operated patients the recurrence rate was 10.9 % (n = 6) compared to 14.9 % (n = 20) in the suture repair group. Cox-regression analysis showed an increased risk for recurrence in the suture repair group (odds ratio 1.43; 95 % CI 0.56-3.57; p = 0.44). Operation time for mesh repair (47 min) was significantly longer compared to suture repair (29 min) (p \ 0.0001). Thirty-seven patients had previous or other anterior wall hernias. A total of 51 patients smoked and 14 patients had diabetes mellitus. Fourteen patients used steroids and 22 patients suffered from a chronic lung disease. Subgroup analysis showed a significant difference for pain in patients in which re-operation for a recurrence occurred (p = 0.004). Conclusions This is one of the largest reported series on solely epigastric hernias. A recurrence occurred more often after sutured repair compared to mesh repair. No differences in chronic pain was seen between mesh and suture repaired patients. Male:female ratio of 1:1, which is different from the 3:1 ratio found in previous older smaller studies, could be more reliable

Femto-photography: capturing and visualizing the propagation of light

We present femto-photography, a novel imaging technique to capture and visualize the propagation of light. With an effective exposure time of 1.85 picoseconds (ps) per frame, we reconstruct movies of ultrafast events at an equivalent resolution of about one half trillion frames per second. Because cameras with this shutter speed do not exist, we re-purpose modern imaging hardware to record an ensemble average of repeatable events that are synchronized to a streak sensor, in which the time of arrival of light from the scene is coded in one of the sensor's spatial dimensions. We introduce reconstruction methods that allow us to visualize the propagation of femtosecond light pulses through macroscopic scenes; at such fast resolution, we must consider the notion of time-unwarping between the camera's and the world's space-time coordinate systems to take into account effects associated with the finite speed of light. We apply our femto-photography technique to visualizations of very different scenes, which allow us to observe the rich dynamics of time-resolved light transport effects, including scattering, specular reflections, diffuse interreflections, diffraction, caustics, and subsurface scattering. Our work has potential applications in artistic, educational, and scientific visualizations; industrial imaging to analyze material properties; and medical imaging to reconstruct subsurface elements. In addition, our time-resolved technique may motivate new forms of computational photography.MIT Media Lab ConsortiumLincoln LaboratoryMassachusetts Institute of Technology. Institute for Soldier NanotechnologiesAlfred P. Sloan Foundation (Research Fellowship)United States. Defense Advanced Research Projects Agency (Young Faculty Award

Compact solid-state CMOS single-photon detector array for in vivo NIR fluorescence lifetime oncology measurements

In near infrared fluorescence-guided surgical oncology, it is challenging to distinguish healthy from cancerous tissue. One promising research avenue consists in the analysis of the exogenous fluorophores’ lifetime, which are however in the (sub-)nanosecond range. We have integrated a single-photon pixel array, based on standard CMOS SPADs (single-photon avalanche diodes), in a compact, time-gated measurement system, named FluoCam. In vivo measurements were carried out with indocyanine green (ICG)-modified derivatives targeting the avb3 integrin, initially on a genetically engineered mouse model of melanoma injected with ICG conjugated with tetrameric cyclic pentapeptide (ICG􀀀E[c(RGDfK)4]), then on mice carrying tumour xenografts of U87-MG (a human primary glioblastoma cell line) injected with monomeric ICG􀀀c(RGDfK). Measurements on tumor, muscle and tail locations allowed us to demonstrate the feasibility of in vivo lifetime measurements with the FluoCam, to determine the characteristic lifetimes (around 500 ps) and subtle lifetime differences between bound and unbound ICG-modified fluorophores (10% level), as well as to estimate the available photon fluxes under realistic conditions

A Compact Probe for Beta+Emitting Radiotracer Detection in Suregery, Biopsy, and Medical Diagnostics based on Silicon Photomultipliers

We present a new probe for radiotracer detection in vivo. The device is based on silicon photomultipliers coupled with a scintillator and wirelessly compensated for supply voltage and temperature variations. The probe is positron sensitive

CAPICE:a computational method for Consequence-Agnostic Pathogenicity Interpretation of Clinical Exome variations

Exome sequencing is now mainstream in clinical practice. However, identification of pathogenic Mendelian variants remains time-consuming, in part, because the limited accuracy of current computational prediction methods requires manual classification by experts. Here we introduce CAPICE, a new machine-learning-based method for prioritizing pathogenic variants, including SNVs and short InDels. CAPICE outperforms the best general (CADD, GAVIN) and consequence-type-specific (REVEL, ClinPred) computational prediction methods, for both rare and ultra-rare variants. CAPICE is easily added to diagnostic pipelines as pre-computed score file or command-line software, or using online MOLGENIS web service with API. Download CAPICE for free and open-source (LGPLv3) at https://github.com/molgenis/capice.

Towards quantum 3d imaging devices

We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusing and ultra-fast, scanning-free, 3D imaging capability of plenoptic devices, along with dramatically enhanced performances, unattainable in standard plenoptic cameras: diffraction-limited resolution, large depth of focus, and ultra-low noise. To further increase the volumetric resolution beyond the Rayleigh diffraction limit, and achieve the quantum limit, we are also developing dedicated protocols based on quantum Fisher information. However, for the quantum advantages of the proposed devices to be effective and appealing to end-users, two main challenges need to be tackled. First, due to the large number of frames required for correlation measurements to provide an acceptable signal-to-noise ratio, quantum plenoptic imaging (QPI) would require, if implemented with commercially available high-resolution cameras, acquisition times ranging from tens of seconds to a few minutes. Second, the elaboration of this large amount of data, in order to retrieve 3D images or refocusing 2D images, requires high-performance and time-consuming computation. To address these challenges, we are developing high-resolution single-photon avalanche photodiode (SPAD) arrays and high-performance low-level programming of ultra-fast electronics, combined with compressive sensing and quantum tomography algorithms, with the aim to reduce both the acquisition and the elaboration time by two orders of magnitude. Routes toward exploitation of the QPI devices will also be discussed

Some Consequences of Thermosolutal Convection: The Grain Structure of Castings

The essential principles of thermosolutal convection are outlined, and how convection provides a transport mechanism between the mushy region of a casting and the open bulk liquid is illustrated. The convective flow patterns which develop assist in heat exchange and macroscopic solute segregation during solidification; they also provide a mechanism for the transport of dendritic fragments from the mushy region into the bulk liquid. Surviving fragments become nuclei for equiaxed grains and so lead to blocking of the parental columnar, dendritic growth front from which they originated. The physical steps in such a sequence are considered and some experimental data are provided to support the argument