Free-induction-decay magnetic field imaging with a microfabricated Cs vapor cell.

Magnetic field imaging is a valuable resource for signal source localization and characterization. This work reports an optically pumped magnetometer (OPM) based on the free-induction-decay (FID) protocol, that implements microfabricated cesium (Cs) vapor cell technology to visualize the magnetic field distributions resulting from various magnetic sources placed close to the cell. The slow diffusion of Cs atoms in the presence of a nitrogen (N2) buffer gas enables spatially independent measurements to be made within the same vapor cell by translating a 175 µm diameter probe beam over the sensing area. For example, the OPM was used to record temporal and spatial information to reconstruct magnetic field distributions in one and two dimensions. The optimal magnetometer sensitivity was estimated to be 0.43 pT/H z within a Nyquist limited bandwidth of 500 Hz. Furthermore, the sensor's dynamic range exceeds the Earth's field of approximately 50 µT, which provides a framework for magnetic field imaging in unshielded environments.

Successful Use of an Exclusion Diet with Partial Enteral Nutrition in a Patient After Total Gastrectomy: A Case Report.

BACKGROUND Gastric cancer is the 5th most common malignancy worldwide. Treatment consists of excision of the entire stomach. Malnutrition is a common problem in patients diagnosed with gastric cancer and has a negative impact on the course of treatment and the quality of life. CASE REPORT The paper presents a case report of a patient after total gastrectomy performed on 11/04/2016 due to G3 mucocellulare carcinoma. The patient had been on home parenteral nutrition for 2.5 years due to chronic malnutrition. After this period of time, an attempt was made to introduce an exclusion diet with the addition of Modulen IBD (Nestle Health Science), which is routinely used in the nutritional treatment of patients with Crohn's disease, with simultaneous discontinuation of parenteral nutrition. After 3 months, the patient was readmitted to the hospital to assess his nutritional status. He continued the diet as recommended. He maintained his body weight and reported improvement in eating habits. CONCLUSIONS In the described case, the patient presented with symptoms of impaired bowel function resulting from long-term cessation of oral nutrition. It is possible that the nutritional and immunomodulatory effect of Modulen, in combination with the anti-inflammatory elimination diet, resulted in better nutrition of intestinal epithelial cells and gradual improvement of intestinal motility and absorption, which in turn enabled the patient to completely withdraw from parenteral nutrition. We propose that this type of nutritional management could also be considered in other cases of intestinal dysfunction.

Automated Machine Learning Strategies for Multi-Parameter Optimisation of a Caesium-Based Portable Zero-Field Magnetometer.

Machine learning (ML) is an effective tool to interrogate complex systems to find optimal parameters more efficiently than through manual methods. This efficiency is particularly important for systems with complex dynamics between multiple parameters and a subsequent high number of parameter configurations, where an exhaustive optimisation search would be impractical. Here we present a number of automated machine learning strategies utilised for optimisation of a single-beam caesium (Cs) spin exchange relaxation free (SERF) optically pumped magnetometer (OPM). The sensitivity of the OPM (T/Hz), is optimised through direct measurement of the noise floor, and indirectly through measurement of the on-resonance demodulated gradient (mV/nT) of the zero-field resonance. Both methods provide a viable strategy for the optimisation of sensitivity through effective control of the OPM's operational parameters. Ultimately, this machine learning approach increased the optimal sensitivity from 500 fT/Hz to <109fT/Hz. The flexibility and efficiency of the ML approaches can be utilised to benchmark SERF OPM sensor hardware improvements, such as cell geometry, alkali species and sensor topologies.

A digital alkali spin maser.

Self-oscillating atomic magnetometers, in which the precession of atomic spins in a magnetic field is driven by resonant modulation, offer high sensitivity and dynamic range. Phase-coherent feedback from the detected signal to the applied modulation creates a resonant spin maser system, highly responsive to changes in the background magnetic field. Here we show a system in which the phase condition for resonant precession is met by digital signal processing integrated into the maser feedback loop. This system uses a modest chip-scale laser and mass-produced dual-pass caesium vapour cell and operates in a 50 [Formula: see text]T field, making it a suitable technology for portable measurements of the geophysical magnetic field. We demonstrate a Cramér-Rao lower bound-limited resolution of 50 fT at 1 s sampling cadence, and a sensor bandwidth of 10 kHz. This device also represents an important class of atomic system in which low-latency digital processing forms an integral part of a coherently-driven quantum system.

The fecal occult blood test as a tool for improved outpatient qualification for colonoscopy. A single-center experience and 10-year follow-up survey.

PURPOSE: Colonoscopy is not widely and easily available in all countries, even for symptomatic patients. This is one of the causes of tumors not being diagnosed until an advanced stage. The aim of this study was to estimate the efficacy of the fecal occult blood test (FOBT) in the diagnostic work-up of outpatients referred to a colorectal unit due to indistinct abdominal symptoms. PATIENTS/METHODS: Among 10418 consecutive symptomatic individuals referred to the outpatient clinic, an immunochemical FOBT (Hem-Check 1®) was recommended for 9432 patients with indistinct symptoms as a tool for qualifying them for colonoscopy. All the subjects were treated according to their diagnosis and followed-up for the next 10 years. RESULTS: Colorectal cancer (CRC) was diagnosed in 535 individuals: 393/986 (39.9%) among patients with red-flag symptoms, and 142/951 (14.9%) of individuals with indistinct symptoms and a positive FOBT. In the latter group, less-advanced tumors, classed as such using Dukes' classification, were twice as common and more advanced CRC occurred twice as seldom than in the former. Cancer recurrence-free and overall survival periods after surgical treatment for CRC were significantly longer in patients with indistinct symptoms who qualified for diagnostic procedures on the basis of a positive FOBT. CONCLUSIONS: Patients with symptoms suggesting organic colon disease had a worse prognosis compared to individuals with non-specific symptoms. If bowel endoscopy is not widely and easily available, qualification for colonoscopy on the basis of alarm symptoms and a positive FOBT seems to be an effective strategy in early CRC diagnosis.

Usefulness of CEA concentration measurement and classic colonoscopy in follow-up after radical treatment of colorectal cancer.

UNLABELLED: There is always a certain rate of recurrence after radical treatment for cancer and to get on it an early detection of disease set back is crucial. MATERIAL AND METHODS: Medical data of patients operated on for primarily detected colorectal cancer in years 1993-2002 was retrospectively reviewed. Usefulness of follow-up means such as physical examination, or CEA and endoscopic surveillance was analyzed. All mentioned above were applied to scheduled follow-up (in 3, 6 and 12 month intervals following an operation and annually after that by the year 5). RESULTS: Complete and reliable data was obtained from 340 out of 502 follow-up intended subjects (67.7%). Elevated CEA was the most frequent predictor of recurrence within non-symptomatic subjects meeting follow-up appointments (60%). The cancer set back diagnosed by means of either physical or endoscopic examinations was the case only in one out of five patients (20.75% and 18.87% respectively). Clinical onset of recurrence making patients meet an unscheduled appointment was found increasing relative risk of nothing-but-palliative option either for them with local set back, or meta-static spread. Relative risk of onset of meta-chronous colonic cancer was significantly higher in patients being affected by synchronous advanced adenoma at time of surgery compared to those with one-fold changes. CONCLUSIONS: CEA scheduled follow-up after treatment for colorectal cancer CRC seems adequate to provide a good outcome of treatment for recurrent tumors. CRC patients presenting with synchronous advanced adenomas at time of surgery are probably to be under more intensive endoscopic surveillance.