Three-dimensional and dual-color fluorescence microscopy on a chip

In this work we present two microscopes on chip based on Light Sheet Fluorescence Microscopy, capable to automatically perform 3D and dual-color imaging of specimens diluted in a liquid suspension. A microfluidic channel is used for automatic sample delivery, while integrated optical components such as optical waveguides and lenses are used to illuminate the sample flowing in the channel. The devices are fabricated by femtosecond laser micromachining in a glass substrate. Benefiting from the versatility of the fabrication technique we present two prototypes that have been optimized for different samples such as single cells and Drosophila embryos

Laparoscopic vs. open mesorectal excision for rectal cancer: Are these approaches still comparable? A systematic review and metaanalysis

Background To analyze pathologic and perioperative outcomes of laparoscopic vs. open resections for rectal cancer performed over the last 10 years. Methods A systematic literature search of the following databases was conducted: Cochrane Central Register of Controlled Trials, MEDLINE (through PubMed), EMBASE, and Scopus. Only articles published in English from January 1, 2008 to December 31, 2018 (i.e. the last 10 years), which met inclusion criteria were considered. The review only included articles which compared Laparoscopic rectal resection (LRR) and Open Rectal Resection (ORR) for rectal cancer and reported at least one of the outcomes of interest. The analyses followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement checklist. Only prospective randomized studies were considered. The body of evidence emerging from this study was evaluated using the Grading of Recommendations Assessment Development and Evaluation (GRADE) system. Outcome measures (mean and median values, standard deviations, and interquartile ranges) were extracted for each surgical treatment. Pooled estimates of the mean differences were calculated using random effects models to consider potential inter-study heterogeneity and to adopt a more conservative approach. The pooled effect was considered significant if p <0.05. Results Five clinical trials were found eligible for the analyses. A positive involvement of CRM was found in 49 LRRs (8.5%) out of 574 patients and in 30 ORRs out of 557 patients (5.4%) RR was 1.55 (95% CI, 0.99–2.41; p = 0.05) with no heterogeneity (I2 = 0%). Incorrect mesorectal excision was observed in 56 out of 507 (11%) patients who underwent LRR and in 41 (8.4%) out of 484 patients who underwent ORR; RR was 1.30 (95% CI, 0.89–1.91; p = 0.18) with no heterogeneity (I2 = 0%). Regarding other pathologic outcomes, no significant difference between LRR and ORR was observed in the number of lymph nodes harvested or concerning the distance to the distal margin. As expected, a significant difference was found in the operating time for ORR with a mean difference of 41.99 (95% CI, 24.18, 59.81; p <0.00001; heterogeneity: I2 = 25%). However, no difference was found for blood loss. Additionally, no significant differences were found in postoperative outcomes such as postoperative hospital stay and postoperative complications. The overall quality of the evidence was rated as high. Conclusion Despite the spread of laparoscopy with dedicated surgeons and the development of even more precise surgical tools and technologies, the pathological results of laparoscopic surgery are still comparable to those of open ones. Additionally, concerning the pathological data (and particularly CRM), open surgery guarantees better results as compared to laparoscopic surgery. These results must be a starting point for future evaluations which consider the association between ‘‘successful resection” and long-term oncologic outcomes. The introduction of other minimally invasive techniques for rectal cancer surgery, such as robotic resection or transanal TME (taTME), has revealed new scenarios and made open and even laparoscopic surgery obsolete

What is the best surgical option for the resection of transverse colon cancer?

Transverse colon is an infrequent localization of colon cancer and it is burdened by a poor prognosis. The principle of oncological radicality includes primary tumor resection with adequate lymphadenectomy. To date, there is still no consensus on which type of surgical resection perform in case of transverse colon cancer (TCC). Lymphatic drainage and vascularization of this section of the colon is highly variable presenting with different anatomical variants. Moreover, mobilization of the transverse colon can be particularly challenging in comparison to other colon tracts. Despite a lack of standardized definitions, three main surgical options are proposed: segmental colectomy of the transverse colon [transverse colectomy (TC)], extended right colectomy (ERC) and subtotal colectomy (STC). The aim of the present review is to describe the outcomes, limitations and advantages of TC, ERC, and STC for TCC in order to identify possible trends in the current literature suggesting which is the best treatment option in both elective and emergency settings

Immunotherapeutic approaches for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a cancer with a high mortality rate due to the fact that the diagnosis usually occurs at anadvanced stage. Even in case of curative surgical treatment, recurrence is common. Sorafenib and regorafenib are the only therapeutic agents that have been demonstrated to be effective in advanced HCC, thus novel curative approaches are urgently needed. Recent studies focus on the role of immune system in HCC. In fact, the unique immune response in the liver favors tolerance, which can represent a real challenge for conventional immunotherapy in these patients. Spontaneous immune responses against tumor antigens have been detected, and new immune therapies are under investigation: dendritic cell vaccination, immune-modulator strategy, and immune checkpoint inhibition. In recent years different clinical trials examining the use of immunotherapy to treat HCC have been conducted with initial promising results. This review article will summarize the literature data concerning the potential immunotherapeutic approaches in HCC patient

The VIMOS VLT Deep Survey :Evolution of the major merger rate since z~1 from spectroscopicaly confirmed galaxy pairs

From the VIMOS VLT Deep Survey we use a sample of 6447 galaxies with I_{AB} < 24 to identify 251 pairs of galaxies, each member with a secure spectroscopic redshift, which are close in both projected separation and in velocity. We find that at z ~ 0.9, 10.9 +/- 3.2 % of galaxies with M_B(z) < -18-Qz are in pairs with separations dr < 20 kpc/h, dv < 500 km/s, and with dM_B < 1.5, significantly larger than 3.76 +/- 1.71 % at z ~ 0.5; we find that the pair fraction evolves as (1+z)^m with m = 2.49 +/- 0.56. For brighter galaxies with M_B(z=0) < -18.77, the pair fraction is higher and its evolution with redshift is somewhat flatter with m=1.88 \pm 0.40, a property also observed for galaxies with increasing stellar masses. Early type, dry mergers, pairs increase their relative fraction from 3 % at z ~ 0.9 to 12 % at z ~ 0.5. We find that the merger rate evolves as N_{mg}=(9.05 +/- 3.76) * 10^{-4}) * (1+z)^{2.43 +/- 0.76}. We find that the merger rate of galaxies with M_B(z) < -18-Qz has significantly evolved since z ~ 1. The merger rate is increasing more rapidly with redshift for galaxies with decreasing luminosities, indicating that the flat evolution found for bright samples is not universal. The merger rate is also strongly dependent on the spectral type of galaxies involved, late type mergers being more frequent in the past, while early type mergers are more frequent today, contributing to the rise in the local density of early type galaxies. About 20 % of the stellar mass in present day galaxies with log(M/M_{sun}) > 9.5 has been accreted through major merging events since z ~ 1, indicating that major mergers have contributed significantly to the growth in stellar mass density of bright galaxies over the last half of the life of the Universe.Comment: 22 pages, 19 figures, accepted in A&

The zCOSMOS 10k-sample: the role of galaxy stellar mass in the colour-density relation up to z=1

[Abridged] With the first 10000 spectra of the flux limited zCOSMOS sample (I<=22.5) we study the evolution of environmental effects on galaxy properties since z=1.0, and disentangle the dependence among galaxy colour, stellar mass and local density (3D local density contrast `delta', computed with the 5th nearest neighbour approach). We confirm that within a luminosity-limited sample (M_B=1) galaxies 'f_red' depends on delta at least up to z=1, with red galaxies residing mainly in high densities. This trend weakens for increasing z, and it is mirrored by the behaviour of the fraction of galaxies with D4000A break >=1.4. We also find that up to z=1 the fraction of galaxies with log(EW[OII]) >=1.15 is higher for lower delta, and also this dependence weakens for increasing z. Given the triple dependence among galaxy colours, stellar mass and delta, the colour-delta relation found in the luminosity-selected sample can be due to the broad range of stellar masses. Thus, we fix the stellar mass and we find that in this case the colour-delta relation is flat up to z=1 for galaxies with log(M/M_sun)>=10.7. This means that for these masses the colour-delta relation found in a luminosity-selected sample is the result of the combined colour-mass and mass-delta relations. In contrast, we find that for 0.1<=z<=0.5 and log(M/M_sun)<=10.7 'f_red' depends on delta even at fixed mass. In these mass and z ranges, environment affects directly also galaxy colours. We suggest a scenario in which the colour depends primarily on stellar mass, but for relatively low mass galaxies the local density modulates this dependence. These galaxies formed more recently, in an epoch when evolved structures were already in place, and their longer SFH allowed environment-driven physical processes to operate during longer periods of time.Comment: 19 pages, 12 figures, submitted to A&A, revised version after referee comment

The zCOSMOS redshift survey: how group environment alters global downsizing trends

Context. Groups of galaxies are a common environment, bridging the gap between starforming field galaxies and quiescent cluster galaxies. Within groups secular processes could be at play, contributing to the observed strong decrease of star formation with cosmic time in the global galaxy population. Aims. We took advantage of the wealth of information provided by the first ~10 000 galaxies of the zCOSMOS-bright survey and its group catalogue to study in detail the complex interplay between group environment and galaxy properties. Methods. The classical indicator F_(blue), i.e., the fraction of blue galaxies, proved to be a simple but powerful diagnostic tool. We studied its variation for different luminosity and mass selected galaxy samples, divided as to define groups/field/isolated galaxy subsamples. Results. Using rest-frame evolving B-band volume-limited samples, the groups galaxy population exhibits significant blueing as redshift increases, but maintains a systematic difference (a lower F_(blue)) with respect to the global galaxy population, and an even larger difference with respect to the isolated galaxy population. However moving to mass selected samples it becomes apparent that such differences are largely due to the biased view imposed by the B-band luminosity selection, being driven by the population of lower mass, bright blue galaxies for which we miss the redder, equally low mass, counterparts. By carefully focusing the analysis on narrow mass bins such that mass segregation becomes negligible we find that only for the lowest mass bin explored, i.e., log(M_*/M_☉) ≤ 10.6, does a significant residual difference in color remain as a function of environment, while this difference becomes negligible toward higher masses. Conclusions. Our results indicate that red galaxies of mass log(M_*/M_☉) ≥ 10.8 are already in place at z ~ 1 and do not exhibit any strong environmental dependence, possibly originating from so-called nature or internal mechanisms. In contrast, for lower galaxy masses and redshifts lower than z ~ 1, we observe the emergence in groups of a population of nurture red galaxies: slightly deviating from the trend of the downsizing scenario followed by the global galaxy population, and more so with cosmic time. These galaxies exhibit signatures of group-related secular physical mechanisms directly influencing galaxy evolution. Our analysis implies that these mechanisms begin to significantly influence galaxy evolution after z ~ 1, a redshift corresponding to the emergence of structures in which these mechanisms take place

The zCOSMOS survey: the role of the environment in the evolution of the luminosity function of different galaxy types

Aims. An unbiased and detailed characterization of the galaxy luminosity function (LF) is a basic requirement in many astrophysical issues: it is of particular interest in assessing the role of the environment in the evolution of the LF of different galaxy types. Methods. We studied the evolution in the B band LF to redshift z ~ 1 in the zCOSMOS 10k sample, for which both accurate galaxy classifications (spectrophotometric and morphological) and a detailed description of the local density field are available. Results. The global B band LF exhibits a brightening of ~0.7 mag in M^* from z ~ 0.2 to z ~ 0.9. At low redshifts (z -20), while the bright end is populated mainly by spectrophotometric early types. At higher redshift, spectrophotometric late-type galaxies evolve significantly and, at redshift z ~ 1, the contribution from the various types to the bright end of the LF is comparable. The evolution for spectrophotometric early-type galaxies is in both luminosity and normalization: M* brightens by ~0.6 mag but φ^∗ decreases by a factor ~1.7 between the first and the last redshift bin. A similar behaviour is exhibited by spectrophotometric late-type galaxies, but with an opposite trend for the normalization: a brightening of ~0.5 mag is present in M^*, while φ^∗ increases by a factor ~1.8.
Studying the role of the environment, we find that the global LF of galaxies in overdense regions has always a brighter M^* and a flatter slope. In low density environments, the main contribution to the LF is from blue galaxies, while for high density environments there is an important contribution from red galaxies to the bright end.
The differences between the global LF in the two environments are not due to only a difference in the relative numbers of red and blue galaxies, but also to their relative luminosity distributions: the value of M^* for both types in underdense regions is always fainter than in overdense environments. These results indicate that galaxies of the same type in different environments have different properties.
We also detect a differential evolution in blue galaxies in different environments: the evolution in their LF is similar in underdense and overdense regions between z ~ 0.25 and z ~ 0.55, and is mainly in luminosity. In contrast, between z ~ 0.55 and z ~ 0.85 there is little luminosity evolution but there is significant evolution in φ^∗, that is, however, different between the two environments: in overdense regions φ^∗ increases by a factor ~1.6, while in underdense regions this increase reaches a factor ~2.8. Analyzing the blue galaxy population in more detail, we find that this evolution is driven mainly by the bluest types. Conclusions. The “specular” evolution of late- and early-type galaxies is consistent with a scenario where a part of blue galaxies is transformed in red galaxies with increasing cosmic time, without significant changes in the fraction of intermediate-type galaxies. The bulk of this tranformation in overdense regions probably happened before z ~ 1, while it is still ongoing at lower redshifts in underdense environments

The bimodality of the 10k zCOSMOS-bright galaxies up to z ~ 1: a new statistical and portable classification based on the optical galaxy properties

Our goal is to develop a new and reliable statistical method to classify galaxies from large surveys. We probe the reliability of the method by comparing it with a three-dimensional classification cube, using the same set of spectral, photometric and morphological parameters.We applied two different methods of classification to a sample of galaxies extracted from the zCOSMOS redshift survey, in the redshift range 0.5 < z < 1.3. The first method is the combination of three independent classification schemes, while the second method exploits an entirely new approach based on statistical analyses like Principal Component Analysis (PCA) and Unsupervised Fuzzy Partition (UFP) clustering method. The PCA+UFP method has been applied also to a lower redshift sample (z < 0.5), exploiting the same set of data but the spectral ones, replaced by the equivalent width of H$\alpha$. The comparison between the two methods shows fairly good agreement on the definition on the two main clusters, the early-type and the late-type galaxies ones. Our PCA-UFP method of classification is robust, flexible and capable of identifying the two main populations of galaxies as well as the intermediate population. The intermediate galaxy population shows many of the properties of the green valley galaxies, and constitutes a more coherent and homogeneous population. The fairly large redshift range of the studied sample allows us to behold the downsizing effect: galaxies with masses of the order of $3\cdot 10^{10}$ Msun mainly are found in transition from the late type to the early type group at $z>0.5$, while galaxies with lower masses - of the order of $10^{10}$ Msun - are in transition at later epochs; galaxies with $M <10^{10}$ Msun did not begin their transition yet, while galaxies with very large masses ($M > 5\cdot 10^{10}$ Msun) mostly completed their transition before $z\sim 1$.Comment: 16 pages, 14 figures, accepted for publication in A&