Effect of oral calcium loading on intact PTH and calcitriol in idiopathic renal calcium stone formers and healthy controls

The calciuric response after an oral calcium load (l000 mg elemental calcium together with a standard breakfast) was studied in 13 healthy male controls and 21 recurrent idiopathic renal calcium stone formers, 12 with hypercalciuria (UCa×V>7.50 mmol/24 h) and nine with normocalciuria. In controls, serum 1,25(OH)2 vitamin D3 (calcitriol) remained unchanged 6 h after oral calcium load (50.6±5.1 versus 50.9±5.0 pg/ml), whereas it tended to increase in hypercalciuric (from 53.6±3.2 to 60.6±5.4 pg/ml, P=0.182) and fell in normocalciuric stone formers (from 45.9±2.6 to 38.1±3.3 pg/ml, P=0.011). The total amount of urinary calcium excreted after OCL was 2.50±0.20 mmol in controls, 2.27±0.27 mmol in normocalciuric and 3.62±0.32 mmol in hypercalciuric stone formers (P=0.005 versus controls and normocalciuric stone formers respectively); it positively correlated with serum calcitriol 6 h after calcium load (r=0.392, P=0.024). Maximum increase in urinary calcium excretion rate, δCa-Emax, was inversely related to intact PTH levels in the first 4 h after calcium load, i.e. more pronounced PTH suppression predicted a steeper increase in urinary calcium excretion rate. Twenty-four-hour urine calcium excretion rate was inversely related to the ratio of δ calcitriol/δPTHmax after calcium load (r=−0.653, P=0.0001), indicating that an abnormally up-regulated synthesis of calcitriol and consecutive relative PTH suppression induce hypercalciuria. Finally, late absorption of calcium as suggested by maximum urinary calcium excretion beyond 4 h after oral calcium load was as rare in hypercalciuric stone formers (2 of 12) as in controls (1 of 13) and did not occur in normocalciuric stone former

The CODE ambiguity-fixed clock and phase bias analysis products: generation, properties, and performance

The generation and use of GNSS analysis products that allowparticularly for the needs of single-receiver applicationsprecise point positioning with ambiguity resolution (PPP-AR) are becoming more and more popular. A general uncertainty concerns the question on how the necessary phase bias information should be provided to the PPP-AR user. Until now, each AR-enabling clock/bias representation method had its own practice to provide the necessary bias information. We have generalized the observable-specific signal bias (OSB) representation, as introduced in Villiger (J Geod 93:14871500, 2019) originally exclusively for pseudorange measurements, to carrier phase measurements. The existing common clock (CC) approach has been extended in a way that OSBs allowing for flexible signal and frequency handling between multiple GNSS become possible. Advantages of the proposed OSB-based PPP-AR approach are: GNSS biases can be provided in a consistent way for phase and code measurements and it is capable of multi-GNSS and suitable for standardization. This new, extended PPP-AR approach has been implemented by the Center for Orbit Determination in Europe (CODE). CODE clock products that adhere to the integer-cycle property have been submitted to the International GNSS Service (IGS) since mid of 2018 for three analysis lines: Rapid, Final, and MGEX (Multi-GNSS Extension). Ambiguity fixing is performed not only for GPS but also for Galileo. The integer-cycle property of between-satellite clock differences is of fundamental importance when comparing satellite clock estimates among various analysis lines, or at day boundaries. Both kinds of comparisons could be exploited at a very high level of consistency. Any retrieved comparison essentially indicated a standard deviation for between-satellite clocks from CODE of the order of 5 ps (1.5 mm in range). Finally, the integer-cycle property that may be recovered between the CODE Final clock and the accompanying bias product of consecutive daily sessions (using clock estimates additionally provided for the second midnight epoch) allows us to deduce GPS satellite clock and phase bias information that is consistent and continuous with respect to carrier phase observation data over two, three, or, in principle, yet more days. Phase-based clock densification from initially estimated integer-cycle-conform clock corrections at intervals of 300 s to 30 s (5 s in case of our Final clock product) is a matter of particular interest. Based on direct product comparisons and GRACE K-band ranging (KBR) data analysis, the quality of accordingly densified clock corrections could be confirmed to be on a level similar to that of of “anchor” (300s) clock corrections

Development of SRF Cavity Tuners for CERN

Superconducting RF cavity developments are currently on-going for new accelerator projects at CERN such as HIE ISOLDE and HL-LHC. Mechanical RF tuning systems are required to compensate cavity frequency shifts of the cavities due to temperature, mechanical, pressure and RF effects on the cavity geometry. A rich history and experience is available for such mechanical tuners developed for existing RF cavities. Design constraints in the context of HIE ISOLDE and HL-LHC such as required resolution, space limitation, reliability and maintainability have led to new concepts in the tuning mechanisms. This paper will discuss such new approaches, their performances and planned developments

The CERN PS multi-turn extraction based on beam splittting in stable islands of transverse phase space: Design Report

Since 2001 considerable effort has been devoted to the study of a possible replacement of the continuous-transfer extraction mode from the PS to the SPS. Such an approach, called Multi-Turn Extraction (MTE), is based on capture of the beam inside stable islands of transverse phase space, generated by sextupoles and octupoles, thanks to a properly chosen tune variation. Both numerical simulations and measurements with beam were performed to understand the properties of this new extraction mode. The experimental study was completed at the end of 2004 and by the end of 2005 a scheme to implement this novel approach in the PS machine was defined and its performance assessed. This design report presents the outcome of the studies undertaken both in terms of technical issues as well as of resources necessary to implement the proposed scheme

Prospective evaluation of the capillaroscopic skin ulcer risk index in systemic sclerosis patients in clinical practice: a longitudinal, multicentre study.

Nailfold capillaroscopy (NC) is an important tool for the diagnosis of systemic sclerosis (SSc). The capillaroscopic skin ulcer risk index (CSURI) was suggested to identify patients at risk of developing digital ulcers (DUs). This study aims to assess the reliability of the CSURI across assessors, the CSURI change during follow-up and the value of the CSURI in predicting new DUs. This multicentre, longitudinal study included SSc patients with a history of DUs. NC images of all eight fingers were obtained at baseline and follow-up and were separately analysed by two trained assessors. Sixty-one patients were included (median observation time 1.0 year). In about 40% of patients (assessor 1, n = 24, 39%; assessor 2, n = 26, 43%) no megacapillary was detected in any of the baseline or follow-up images; hence the CSURI could not be calculated. In those 34 patients in whom CSURI scores were available from both assessors (26% male; median age 57 years) the median baseline CSURI was 5.3 according to assessor 1 (IQR 2.6-16.3), increasing to 5.9 (IQR 1.3-12.0) at follow-up. According to assessor 2, the CSURI diminished from 6.4 (IQR 2.4-12.5) to 5.0 (IQR 1.7-10.0). The ability of a CSURI ≥ 2.96 category to predict new DUs was low (for both assessors, positive predictive value 38% and negative predictive value 50%) and the inter-assessor agreements for CSURI categories were fair to moderate. In this study, around 40% of patients could not be evaluated with the CSURI due to the absence of megacapillaries. Clinical decisions based on the CSURI should be made with caution. Current Controlled Trials, ISRCTN04371709 . Registered on 18 March 2011

Installation and Hardware commissioning of the Multi-Turn extraction at the CERN proton synchrotron

The implementation of the new Multi-Turn Extraction (MTE) at the CERN Proton Synchrotron required major hardware changes for the nearly 50-year old accelerator. The installation of new Pulse Forming Networks (PFN) and refurbished kicker magnets for the extraction, new sextupole and octupole magnets, new power converters, together with an in-depth review of the machine aperture leading to the design of new vacuum chambers was required. As a result, a heavy programme of interventions had to be scheduled during the winter shut-down 2007-8. The newly installed hardware and its commissioning is presented and discussed in details