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NIST’s C-series isoperibol calorimeters [1] operating at room temperature have been used as reference instruments in the laser power calibrations at NIST for over 50 years. These calorimeters operate from 100 μW to 300 mW with an expanded uncertainty of 0.86% (k = 2). Recently developed vertically aligned carbon-nanotube (VACNT) absorbers, with spectrally flat and hemispherical absorptance better than 99.95%, have enabled development of planar absolute bolometers with smaller size and significantly faster measurements compared to traditional laser calorimeters. In this work, we present the latest progress of the Planar Absolute Radiometer for Room Temperature (PARRoT) [2] currently under construction that will replace the old reference C-series calorimeters. PARRoT is based on the electrical power substitution method and it can measure laser powers up to 300 mW with a predicted expanded uncertainty better than 0.1% (k = 2). The radiometer is operated at room temperature and placed in a 15 cm cube vacuum chamber to minimize convection while still providing a compact and sturdy standard. The laser beam is transmitted to the absorber by an uncoated fused silica window with a 0.5° wedge assuring polarization independent laser power detection. PARRoT is background compensated by differential operation where the reference detector chip is driven by a constant DC power and the measuring detector chip is feedback controlled to follow the temperature of the reference detector chip. The closed loop operation makes the radiometer’s response linear across the operational power range. We have optimized the detector chip design by thermal modeling [2]. The modeled electro-optical inequivalence for a centered laser beam is 0.007% and the spatial non-uniformity is ±0.02% within 4 mm radius from the absorber’s center, meaning that PARRoT is not sensitive to small alignment offsets. PARRoT’s differential background compensation makes it insensitive to variations in background radiation. That combined with a compact design would allow it to be used as a radiance detector standard for field calibrations and atmospheric measurements outdoors or as a transfer standard between laboratories. Similar bolometers will be launched in a CubeSat satellite next year to measure total solar irradiance [3]. By changing a few resistance values in the electronics, by changing the detector chip’s heater resistance, and modifying the thermal conductance of the heat link design, the power range of PARRoT can be modified for different applications without compromising the accuracy. For example, reducing the heater resistance and increasing the heat link’s thermal conductance can extend the power range to 2 W. This enables, for instance, direct calibration of the 1 W laser beam power in LIGO (Laser Interferometer Gravitational-wave Observatory) with an expanded uncertainty of 0.1% (k = 2) which would be an order of magnitude improvement to its current calibration against NIST’s reference calorimeter via an integrating sphere transfer standard. Acknowledgements: Jenny and Antti Wihuri Foundation, Finland is acknowledged for the financial support of this research. 1. E. D. West et al., “A Reference Calorimeter for Laser Energy Measurements,” J. Res. Natl. Bur. Stand. (U. S.) 76A, 13–26 (1972). 2. A. Vaskuri et al., “Microfabricated bolometer based on a vertically aligned carbon nanotube absorber,” Proc. SPIE 11269, 1–12, Synthesis and Photonics of Nanoscale Materials XVII, 112690L (March 2020). 3. D. Harber et al., “Compact total irradiance monitor flight demonstration,” Proc. SPIE 11131, 1–8, CubeSats and SmallSats for Remote Sensing III, 111310D (August 2019).

An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies the frequency of the optical clock transition, and often represents a large contribution to a clock's uncertainty budget. For clocks based on singly-ionized ytterbium, the ion's complex structure makes this shift difficult to calculate theoretically. We present a measurement of the differential polarizabilities of two ultra-narrow optical clock transitions present in $^{171}\mathrm{Yb}^+$, performed by exposing the ion to an oscillating electric field at a wavelength in the region of room temperature BBR spectra. By measuring the frequency shift to the transitions caused by a laser at $\lambda=7.17 \mu m$, we obtain values for scalar and tensor differential polarizabilities with uncertainties at the percent level for both the electric quadrupole and octupole transitions at 436nm and 467nm respectively. These values agree with previously reported experimental measurements and, in the case of the electric quadrupole transition, allow a 5-fold improvement in the determination of the room-temperature BBR shift. However, we note significant concerns over the validity of the uncertainty charactarization presented and draw the reader's attention to the Note on applicability section for a discussion.

Background: One of the rarest tumors of the parotid gland is a Small Cell Carcinoma (SmCC) of neuroendocrine or ductal origin. These lesions tend to be aggressive, often invading bone and nerve and carry a grave prognosis for the patient. Presently there is no standardized treatment protocol and no consensus to tumor management. Case Report: This case report is of a 70 year-old male with a right-sided facial mass, facial pain, severe otalgia, weight loss, and right-sided facial paralysis. Subsequent imaging and Fine Needle Aspiration (FNA) revealed T4aN2bM0 SmCC of the parotid gland with facial nerve enhancement and skull base erosion. The patient underwent major extirpative surgery including radical neck dissection, total parotidectomy with facial nerve resection and cable graft, and partial temporal bone resection as the initial step in a combined modality therapy The patient has done very well post-operatively. Conclusion: This case report describes the successful, aggressive surgical management of locally and regionally advanced SmCC of the parotid gland. Although the prognosis for patients with SmCC of the parotid gland is typically grave, the absence of distant metastatic disease in the presented case provided the rationale for an aggressive surgical approach with a curative, rather than palliative, focus.

The Stark shift due to blackbody radiation (BBR) is the key factor limiting the performance of many atomic frequency standards, with the BBR environment inside the clock apparatus being difficult to characterize at a high level of precision. Here we demonstrate an in-vacuum radiation shield that furnishes a uniform, well-characterized BBR environment for the atoms in an ytterbium optical lattice clock. Operated at room temperature, this shield enables specification of the BBR environment to a corresponding fractional clock uncertainty contribution of $5.5 \times 10^{-19}$. Combined with uncertainty in the atomic response, the total uncertainty of the BBR Stark shift is now $1\times10^{-18}$. Further operation of the shield at elevated temperatures enables a direct measure of the BBR shift temperature dependence and demonstrates consistency between our evaluated BBR environment and the expected atomic response., Comment: 5 pages, 3 figures, accepted to PRL

Von Hippel-Lindau disease is an autosomal dominant disorder caused by a mutation of VHL gene. The incidence of the disease is one in 36,000 and its clinical manifestation is a familial occurrence of hemangioblastoma of the central nervous system and retina, renal cell cancer and pheochromocytoma. Cerebellar hemangioblastoma is the most frequent or sometimes the only abnormality observed in this syndrome. We present a family with von Hippel-Lindau disease in which four first degree relatives had a cerebellar hemangioblastoma. This neoplasm caused the death of two brothers aged 27 and 24 years old, respectively and their mother aged 62. The third son of this family was affected ten years ago, at the age of 30. The healthy family members are counselled in Oncological Genetic Outpatient Unit in Gdańsk.

We describe the results of a comparison of reference standards between the National Institute of Standards and Technology (NIST-USA) and National Institute of Metrology (NIM-China). We report optical fiber-based power measurements at nominal wavelengths of 1310 nm and 1550 nm. We compare the laboratories' reference standards by means of a commercial optical power meter. Measurement results showed the largest difference of less than 2.6 parts in 10(3), which is within the combined standard (k = 1) uncertainty for the laboratories' reference standards.

The authors describe a rare case of subdural haematoma in a patient with dural carcinomatosis associated with a primary carcinoma of the pancreas. The diagnosis of the intracranial lesion was established by carotid angiography and the patient was operated on but died 2 weeks after operation because of upper gastrointestinal haemorrhage. It is thought that the subdural fluid accumulation resulted from the occlusion of the dural capillaries with neoplastic cells with subsequent haemorrhages.

The Bulletin of Zoological Nomenclature, Volume 19, Issue 2, pp. 66-67

Meningiomas exhibit a tendency to the local regrowth after their surgical resection, and some of those recurrent tumors show histological malignancy progression. The present study was performed on 10 cases of recurrent meningiomas chosen out of total 122 meningiomas diagnosed in our Department of Pathomorphology in the period 1993-1998. The tissue material from both operations was examined. One patient was operated three times. In three cases at the second operation there was progression from benign to atypical meningioma. The other tumors did not change their histological grade (four benign, one atypical and two anaplastic). The tumor tissue section were stained immunohistochemically with monoclonal antibodies raised against epithelial membrane antigen (EMA), Ki-67 and von Willebrand factor (vWf). The percentage of EMA-positive cells and Ki-67 immunoreactive cells (proliferation cell index--PCI) were counted. The vascular density (number of blood vessels/mm2) was assessed in the preparations stained with anti-vWf, as the measure of the intensity of angiogenesis. The values of the examined parameters were greatly differentiated within both the initial and the recurrent tumor groups. The values of vascular density ranged 12-96 vessels/mm2, the percentage of EMA-positive cells was 0.75%, PCI was from 0.3 to 9.3%. The values of the examined parameters did not differ significantly between initial and recurrent meningiomas groups. It is however worth to point out that PCI in the most recurrent tumors were higher than in their primary counterparts.

The authors examined multiple brain sections from 15 autopsy cases of AIDS for the vascular changes, presence of amyloid plaques and signs of axonal damage. The mean patients age was 33.8 years (range 24-48 years). Neuropathological findings included: HIV-specific changes (5), opportunistic infections (7), lymphoma (1) and two cases with nonspecific changes. All sections were stained with hematoxylin-eosin (H-E), selected sections were stained with Masson trichrome, Gomori reticulin, Congo red and thioflavine S method. Two sections from each case were immunostained for the presence of beta-amyloid (4G8). ubiquitin, alpha-smooth muscle actin and CD31. The different forms of vascular changes were found in all cases. The common changes were: lymphocytic perivascular or transmural infiltrations and hyalinization, thickening or fibrosis of the arterial and arteriolar wall. The perivascular space widening up to status lacunaris was a frequent phenomenon in the basal ganglia and deep white matter. Some of the cortical arterioles formed little multiluminal structures. Immunohistochemical examination revealed features of hypertrophy of the vascular muscular layer and signs of the slight endothelial cells proliferation. In three cases 4G8 immunopositive. Congo red and thioflavine S-negative, diffuse beta-amyloid deposits were present in the gray matter, focally their localization was perivascular. Ubiquitin immunoreactivity presented as numerous dot-like structures or focal bundles of positive widened axons in the white matter, spheroids and scattered positive neurons were also found. The authors suggest that some of morphological changes within the brain and consecutive neuropsychological symptoms in AIDS are of the vascular origin. Presence of amyloid plaques and axonal damage are the elements of the complex degenerative and inflammatory process in the brain caused by chronic inflammatory stimulation in HIV infection.

The aim of the present study was to investigate the intensity of angiogenesis and p53 protein expression in metastases of lung cancer to the brain. There were eight cases of squamous cell type and nine adenocarcinomas among 17 examined cases of metastatic carcinomas. The antibodies against von Willebrand factor (vWF)--to highlight the microvessels and against p53 protein--for detection of immunopositive cells were used. The intensity of angiogenesis was represented by the mean number of the blood vessels in three tumor fields with the highest microvascular density ("hot spots"). The measurements were taken in three microscopic fields under 200x magnification (the examined area was 0.785 mm2). The mean number of p53-positive cells in three tumor areas under 200x magnification with the highest number of p53-positive cells was the measure of protein p53 expression. The values of vascular density and p53 expression differed a lot among the examined tumors. The values of vascular density were between 4.2-106 vessels/mm2 (mean value 49.3 vessel/mm2). The number of p53-immunopositive cells was between 0-284 cells/mm2 (mean value 110.6 cells/mm2). There was no significant correlation between examined parameters (correlation coefficient 0.18).