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The notion of an anonymous shared memory (recently introduced in PODC 2017) considers that processes use different names for the same memory location. As an example, a location name A used by a process p and a location name B = A used by another process q can correspond to the very same memory location X, and similarly for the names B used by p and A used by q which may (or may not) correspond to the same memory location Y = X. Hence, there is permanent disagreement on the location names among processes. In this context, the PODC paper presented -among other results-a symmetric deadlock-free mutual exclusion (mutex) algorithm for two processes and a necessary condition on the size m of the anonymous memory for the existence of a symmetric deadlock-free mutex algorithm in an n-process system. This condition states that m must be greater than 1 and belong to the set M (n) = {m : ∀ ℓ : 1 < ℓ ≤ n : gcd(ℓ, m) = 1} (symmetric means that, while each process has its own identity, process identities can only be compared with equality).The present paper answers several open problems related to symmetric deadlock-free mutual exclusion in an n-process system (n ≥ 2) where the processes communicate through m registers. It first presents two algorithms. The first considers that the registers are anonymous read/write atomic registers and works for any m greater than 1 and belonging to the set M (n). Hence, it shows that this condition on m is both necessary and sufficient. The second algorithm considers that the registers are anonymous read/modify/write atomic registers. It assumes that m ∈ M (n). These algorithms differ in their design principles and their costs (measured as the number of registers which must contain the identity of a process to allow it to enter the critical section). The paper also shows that the condition m ∈ M (n) is necessary for deadlock-free mutex on top of anonymous read/modify/write atomic registers. It follows that, when m > 1, m ∈ M (n) is a tight characterization of the size of the anonymous shared memory needed to solve deadlock-free mutex, be the anonymous registers read/write or read/modify/write.

Presently, tissue engineering has been developed as an effective option in the restoration and repair of tissue defects. One of the tissue engineering strategies is to use both biodegradable scaffolds and stimulating factors for enhancing cell responses. In this study, the effect of zeolite was assessed on cell viability, proliferation, osteo/odontogenic differentiation, and mineralization of human dental pulp stem cells (hDPSCs) cultured on poly (e-coprolactone)poly (ethylene glycol)-poly (e-caprolactone) (PCL-PEG-PCL) nanofibers. For this purpose, PCL-PEG-PCL nanofibrous scaffolds incorporated with zeolite were prepared via electrospinning. Both PCL-PEG-PCL and PCL-PEG-PCL/Zeolite nanofibrous scaffolds revealed bead-less constructions with average diameters of 430 nm and 437 nm, respectively. HDPSCs were transferred to PCL-PEG-PCL nanofibrous scaffolds containing zeolite nanoparticles. Cell adhesion and proliferation of hDPSCs and their osteo/odontogenic differentiation on these scaffolds were evaluated using MTT assay, Alizarin red S staining, and qRT-PCR assay. The results revealed that PCL-PEG-PCL/Zeolite nanofibrous scaffolds could support better cell adhesion, proliferation and osteogenic differentiation of hDPSCs and as such is expected to be a promising scaffold for bone tissue engineering applications.

Background Microcapsule is considered as a promising 3D microenvironment for Bone Tissue Engineering (BTE) applications. Microencapsulation of cells in an appropriate scaffold not only protected the cells against excess stress but also promoted cell proliferation and differentiation. Through the current study, we aimed to microcapsulate the human Dental Pulp Stem Cells (hDPSCs) and evaluated the proliferation and osteogenic differentiation of those cells by using MTT assay, qRT-PCR, Alkaline phosphatase, and Alizarine Red S. Results The SEM results revealed that Alg/Gel microcapsules containing nHA showed a rough and more compact surface morphology in comparison with the Alg/Gel microcapsules. Moreover, the microencapsulation by Alg/Gel/nHA could improve cell proliferation and induce osteogenic differentiation. The cells cultured in the Alg/Gel and Alg/Gel/nHA microcapsules showed 1.4-fold and 1.7-fold activity of BMP-2 gene expression more in comparison with the control group after 21 days. The mentioned amounts for the BMP-2 gene were 2.5-fold and 4-fold more expression for the Alg/Gel and Alg/Gel/nHA microcapsules after 28 days. The nHA, addition to hDPSCs-laden Alg/Gel microcapsule, could up-regulate the bone-related gene expressions of osteocalcin, osteonectin, and RUNX-2 during the 21 and 28 days through the culturing period, too. Calcium deposition and ALP activities of the cells were observed in accordance with the proliferation results as well as the gene expression analysis. Conclusion The present study demonstrated that microencapsulation of the hDPSCs inside the Alg/Gel/nHA hydrogel could be a potential approach for regenerative dentistry in the near future. Graphical abstract

We devise a technique for augmenting shared objects in the standard n-process shared memory model with a linearizable write() operation, using bounded space and optimal worstcase step complexity. We provide a transformation of any shared object SW supporting only sequential write() operations into an object W that supports concurrent write() operations. This transformation requires O(n 2 ) SW objects and O(n 2 ) O(log n)-bit registers, and each method (including write()) has, up to a constant additive term, the same time complexity as the corresponding method on object SW . Our implementation is deterministic, wait-free, and uses only shared registers (supporting atomic read and write operations). To the best of our knowledge, similarly efficient general constructions are not known even if stronger primitives such as CAS or LL/SC are available.Applying our transformation, we obtain an implementation of a k-word register from O(n 2 · k) single-word registers. As another application we can transform one-time TAS objects (e.g., randomized wait-free implementations that use a bounded number of registers [8,9]), into long-lived ones using also a bounded number of registers. The transformation preserves the time complexity of TAS() operations and allows resets in constant worst-case time.Our transformation employs a novel memory reclamation technique, which can replace Hazard Pointers [20] and is more efficient.

Treatment with M2000 in combination with conventional therapy showed a significantly superior efficacy along with a high safety profile compared to conventional-treated patients. Thereby, M2000 might be suggested as a suitable option in the treatment of RA.

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