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Abstract Objectives We aimed to test the hypothesis that in retroperitoneal dedifferentiated liposarcoma (DDLS) the presence of the dedifferentiated (DD) component at the resection margin is associated with adverse outcome. Methods We retrospectively searched the archive for primary resections of retroperitoneal DDLS performed at our institution between 1990 and 2017. Slides were rereviewed for diagnosis, Fédération Nationale des Centres de Lutte Contre le Cancer grade, myogenic differentiation, and the presence of the well-differentiated (WD) or DD component at the resection margin. The medical records were reviewed for patient age, sex, tumor size, tumor focality, adjuvant/neoadjuvant therapy, local recurrence, distant metastases, local recurrence-free survival (LRFS), overall survival (OS), and follow-up duration. Results The presence of the DD component at the resection margin was associated with worse LRFS compared with cases without the DD component at the margin (P = .002). However, OS was not significantly affected (P = .11). Conclusions LRFS is significantly shorter in cases with the DD component at the margin compared with cases without DD tumor at the margin, while there is no association with OS. We recommend reporting the presence or absence of DD tumor at the margin in retroperitoneal DDLS, as it adds meaningful prognostic information.

This paper presents an analysis for a multi-stage Low Noise Amplifier (LNA) for application on deep brain stimulation. A low noise amplifier (LNA) with high gain, moderate bandwidth and reduced noise is designed and simulated using LT Spice and PTM BSIM4 CMOS models. The novel LNA circuit topology is proposed which uses a cascaded style to improve mid-band gain of an LNA. The proposed LNA achieves a gain margin which ranges between 60-67 (dB), 2X times; Phase Margin which ranges between 145 to 154 (deg), 3X times; Gain which ranges between 66 to 75 (dB), 2X times and bandwidth from kHz to MHz range. The current biasing circuit is used for enhancing stability and gain range. Also, optimal noise figure is achieved with the help of cascading input matching along with source degeneration technique.

Plate tectonics theory, established in the 1960s, has been successful in explaining many geological phenomena, processes and events that occurred in the Phanerozoic. However, the theory has often struggled to provide a coherent framework in interpreting geological records in continental interior and Precambrian period. In dealing with the relationship between plate tectonics and continental geology, continental interior tectonics was often separated from continental margin tectonics in the inheritance and development of their structure and composition. This separation led to the illusion that the plate tectonics theory is not applicable to Precambrian geology, particularly in explaining the fundamental geological characteristics of Archean cratons. Although this illusion does not mean that the Archean continental crust did not originate from a regime of plate tectonics, it led to the development of alternative tectonic models, often involving vertical movements under a regime of stagnant lid tectonics, including not only endogenous processes such as gravitational sagduction, mantle plumes and heat pipes but also exogenous processes such as bolide impacts. These vertical processes were not unique to the Archean but persisted into the Phanerozoic. They result from mantle poloidal convection at different depths, not specific to any particular period. Upgrading the plate tectonics theory from the traditional kinematic model in the 20th century to a holistic kinematic-dynamic model in the 21st century and systematically examining the vertical transport of matter and energy at plate margins, it is evident that plate tectonics can explain the common geological characteristics of Archean cratons, such as lithological associations, structural patterns and metamorphic evolution. By deciphering the structure and composition of convergent plate margins as well as their dynamics, the formation and evolution of continental crust since the Archean can be divided into ancient plate tectonics in the Precambrian and modern plate tectonics in the Phanerozoic. In addition, there are the following three characteristic features in the Archean: (1) convective mantle temperatures were 200–300°C higher than in the Phanerozoic, (2) newly formed basaltic oceanic crust was as thick as 30–40 km, and (3) the asthenosphere had a composition similar to the primitive mantle rather than the depleted mantle at present. On this basis, the upgraded plate tectonics theory can successfully explain the major geological phenomena of Archean cratons. This approach provides a new perspective on and deep insights into the evolution of early Earth and the origin of continental crust. In detail, Archean tonalite-trondhjemite-granodiorite (TTG) rocks would result from partial melting of the over-thick basaltic oceanic crust at convergent plate margins. The structural patterns of gneissic domes and greenstone keels would result from the buoyancy-driven emplacement of TTG magmas and its interaction with the basaltic crust at convergent margins, and komatiites in greenstone belts would be the product of mantle plume activity in the regime of ancient plate tectonics. The widespread distribution of high-grade metamorphic rocks in a planar fashion, rather than in zones, is ascrible to separation of the gneissic domes from the greenstone belts. The shortage of calc-alkaline andesites in bimodal volcanic associations suggests the shortage of sediment accretionary wedges derived from weathering of granitic continental crust above oceanic subduction zones. The absence of Penrose-type ophiolites suggests that during the subduction initiation of microplates, only the upper volcanic rocks of the thick oceanic crust were offscrapped to form basalt accretionary wedges. The absence of blueschist and eclogite as well as classic paired metamorphic belts suggests that convergent plate margins were over-thickened through either warm subduction or hard collision of the thick oceanic crust at moderate geothermal gradients. Therefore, only by correctly recognizing and understanding the nature of Archean cartons can plate tectonics reasonably explain their fundamental geological characteristics.

Background The study determined the proportion of patients with pancreatic adenocarcinoma (PDAC) who had margin-positive disease and no other adverse pathologic findings (APF) using institutional and administrative datasets. Methods Patients with clinical stage I or II PDAC in the National Cancer Database (NCDB 2010–2020) and those who underwent pancreatectomy at the authors’ institution (2010–2021) were identified. Isolated margin positivity (IMP) was defined as a positive surgical margin with no APF (negative nodes, no lymphovascular/perineural invasion). Results The study included 225 patients from the authors’ institution and 23,598 patients from the NCDB. The margin-positive rates were 21.8% and 20.3%, and the IMP rates were 0.4% and 0.5%, respectively. In the institutional cohort, 68.4% of the patients had recurrence, and most of the patients (65.6%) had distant recurrences. The median recurrence-free survival (RFS) was 63.3 months for no APF, not reached for IMP, 14.8 months for negative margins & 1 APF, 20.3 months for positive margins & 2 APFs, and 12.9 months with all APF positive. The patients in the NCDB with IMP had a lower median OS than the patients with no APF (20.5 vs 390 months), but a higher median OS than those with margin positivity plus 1 APF (20.5 vs 18.0 months) or all those with APF positivity (20.5 vs 15.4 months). Based on institutional rates of IMP, any margin positivity, neck margin positivity (NMP), and no APF, the fraction of patients who might benefit from neck margin revision was 1 in 100,000, and those likely to benefit from any margin revision was 1 in 18,500. In the NCDB, those estimated to derive potential benefit from margin revision was 1 in 25,000. Conclusions Isolated margin positivity in resected PDAC is rare, and most patients experience distant recurrence. Revision of IMP appears unlikely to confer benefit to most patients.

Both mantle plumes and passive margin extension have been recognized as crucial mechanisms governing intracontinental volcanism and lithospheric evolution. However, the synergistic interactions between these two processes in modulating lithospheric modification remain poorly constrained. The Leiqiong volcanic area (LQV), on the northern continental margin of the South China Sea, has witnessed intense volcanic activity since the late Cenozoic. Though geophysical imaging show mantle plume beneath LQV, limited resolution hinders our understanding of lithospheric modification and magmatic processes. In this study, analysis of teleseismic waveforms from newly deployed broadband stations reveals the lithospheric thinning to the south of LQV, crustal thinning, high stretching factors, high Vp/Vs ratios and crustal melting within LQV. In comparison with global hotspots modulating lithospheric architecture and melting, our results offer seismological evidence that passive margin dynamics rival mantle plumes in lithospheric modification, highlighting a plume‐lithosphere interaction that jointly drives volcanism and continental margin destabilization through multi‐mechanisms.

Characteristics of cold seeps at different geologic settings are the subject of this review primarily based on results of the Research Consortium SFB 574. Criteria are drawn from examples on the erosive convergent margin off Costa Rica, the accretionary margin off Chile supplemented by examples from the transform margin of the Golf of Cadiz and the convergent Hikurangi margin off New Zealand. Others are from well-studied passive margins of the Black Sea, the Golf of Mexico, the eastern Mediterranean Sea and the South China Sea. Seeps at all settings transport water and dissolved compounds to the ocean through the seafloor by different forcing mechanism and from different depths of the submerged geosphere (10s of meters to 10s of km). The compounds sustain oasis-type ecosystems by providing bioactive reductants sulfide, methane and hydrogen. Hereby, the interaction between fluid composition, flux rates and biota results in a diagnostic hydrocarbon–metazoan–microbe–carbonate association; currently, well over 100 active sites are known. The single most important reaction is microbially mediated anaerobic oxidation of methane with secondary reactions involving S-biogeochemistry and carbonate mineral precipitation. Seep fluids and their seafloor manifestations provide clues as to source depth, fluid–sediment/rock interaction during ascent, lifetime and cyclicity of seepage events but less so on the magnitude of return flow. At erosive margins, Cl-depleted and B-enriched fluids from clay dehydration provide criteria for source depth and temperature. The upward material flow generates mud volcanoes at the seafloor above the projected location of dehydration at depth. At accretionary margins, fluids are derived from more shallow depths by compaction of sediments as they ride on the incoming oceanic plate; they are emitted through thrust faults. At highly sedimented margins, organic-rich and evaporite-containing strata (when present) determine the final fluid composition, by emitting characteristically gas hydrate-derived methane, brine-associated non-methane hydrocarbons or leached elements and their isotopes (Li, δ 7 Li, B, Ba) from host sediments. Smectite–illite transformation and associated Cl-depletion from release of interlayer water is a pervasive process at these margins. Rare earth element pattern in conjunction with redox-sensitive metals retained in seep carbonates indicate whether or not they precipitated in contact with oxic bottom water or suboxic fluids; clear environmental characterization, though, currently remains inconclusive. More deeply sourced fluids as in transform margins may be characterized by their 87 Sr/ 86 Sr ratios from interaction with oceanic crustal rocks below. Quantification of flow and reliable estimates of total volatile output from fore-arcs remain a challenge to seep research, as does understanding the role of geologically derived methane in the global methane cycle.

Introduction Although a positive surgical margin is a known prognostic factor for recurrence, the optimal surgical margin width in the context of an R0 resection for early-stage hepatocellular carcinoma (HCC) is still debated. The aim of the current study was to examine the impact of wide ( >  1 cm) versus narrow (< 1 cm) surgical margin status on the incidence and recurrence patterns among patients with T1 HCC undergoing an R0 hepatectomy. Methods Between 1998 and 2017, patients with T1 HCC who underwent R0 hepatectomy for stage T1 HCC were identified using an international multi-institutional database. Recurrence-free survival (RFS) was estimated, and recurrence patterns were examined based on whether patients had a wide versus narrow resection margins. Results Among 404 patients, median patient age was 66 years (IQR: 58–73). Most patients ( n  = 326, 80.7%) had surgical margin < 1 cm, while 78 (19.3%) patients had a >  1 cm margin. The majority of patients had early recurrences (< 24 months) in both margin width groups (< 1 cm: 70.3% vs >  1 cm: 85.7%, p  = 0.141); recurrence site was mostly intrahepatic (< 1 cm: 77% vs >  1 cm: 61.9%, p  = 0.169). The 1-, 3-, and 5-year RFS among patients with margin < 1 cm were 77%, 48.9%, and 35.3% versus 81.7%, 65.8%, and 60.7% for patients with margin >  1 cm, respectively ( p  = 0.02). Among patients undergoing anatomic resection, resection margin did not impact RFS (3-year RFS: < 1 cm: 49.2% vs >  1 cm: 58.9%, p  = 0.169), whereas in the non-anatomic resection group, margin width >  1 cm was associated with a better 3-year RFS compared to margin < 1 cm (86.7% vs 47.3%, p  = 0.017). On multivariable analysis, margin >  1 cm remained protective against recurrence (HR = 0.50, 95%CI 0.28–0.89), whereas Child-Pugh B (HR = 2.13, 95%CI 1.09–4.15), AFP >  20 ng/mL (HR = 1.71, 95%CI 1.18–2.48), and presence of microscopic lymphovascular invasion (HR = 1.48, 95%CI 1.01–2.18) were associated with a higher hazard of recurrence. Conclusion Resection margins >  1 cm predicted better RFS among patients undergoing R0 hepatectomy for T1 HCC, especially small (< 5 cm) HCC. Although resection margin width did not influence outcomes after anatomic resection, wider margins were more important among patients undergoing non-anatomic liver resections.

There has been a long debate about how passive (Atlantic‐type) margins can convert to active (Andean) margins, particularly if they can do so directly, or some other process such as an arc‐continent collision must intervene (Burke et al., 1984; Dewey, 1969, https://doi.org/10.1016/0012‐821x(69)90089‐2; Kusky & Kidd, 1985). Most numerical models have long‐suggested that only very young passive margins can be sites of subduction initiation since old margins become stronger as they cool and develop thick sedimentary piles during thermal subsidence (e.g., Cloetingh et al., 1982, https://doi.org/10.1038/297139a0, 1989, https://doi.org/10.1007/bf00874622; 1996; Zhong & Li, 2019, https://doi.org/10.1029/2019gl084022), whereas other analog and numerical models have suggested that old passive margins may spontaneously convert to subduction zones (e.g., Bercovici & Mulyukova, 2021, https://doi.org/10.1073/pnas.2011247118; Faccenna et al., 1999, https://doi.org/10.1029/1998jb900072; Nikolaeva et al., 2010, https://doi.org/10.1029/2009jb00654; Stern & Gerya, 2018, https://doi.org/10.1016/j.tecto.2017.10.014; Zhang et al., 2023, https://doi.org/10.1029/2023gl103553). Plain Language Summary How do passive margins convert to active margins? The evidence presented by Zeng et al. (2025), https://doi.org/10.1029/2025gc12197 and a survey of the literature about past well‐documented events overwhelmingly points to the process of arc‐polarity reversal following arc‐continent collision. The time frame of such events is such that they usually start very soon after or even during the late stages of collision, and the process is typically complete within 10–20 million years (e.g., Brown & Ryan, 2011, https://doi.org/10.1007/978‐3‐540‐88558‐0). The shortest documented cases (5–10 million years) include Timor, Taiwan, and the Proterozoic Wopmay orogen, with the longest cases (25–30 million years) including the Urals and Kohistan (Brown & Ryan, 2011, https://doi.org/10.1007/978‐3‐540‐88558‐0). Intermediate durations (∼10–12 million years) of collision to arc polarity reversal include Kamchatka, and the Grampian and Taconic collisions, as discussed above. The evidence is clear: passive margins rapidly convert to active (Andean) margins by subduction polarity reversal following arc‐continent (with passive margin) collision. Key Points Passive margins convert to active margins after collisions with arcs and subduction polarity reversal No examples are known of spontaneous subduction initiation at passive margins Zeng et al. (2025, https://doi.org/10.1029/2025gc12197) present a new example of subduction initiation and subduction polarity reversal after arc collision with passive margin

In patients undergoing mastectomy for ductal carcinoma in situ (DCIS), the significance of a positive or close (<2 mm) margin and associated recurrence risk is unclear. The study sought to evaluate risk of recurrence in relation to the mastectomy surgical margin. A single institution retrospective review of patients with DCIS who underwent mastectomy between 2000 and 2010 was performed. Patient demographics, tumor biology, margin status and adjuvant therapy were recorded. The incidence of local recurrence (LR), distant metastasis were analyzed. A total of 282 patients with DCIS were identified. Overall, 12.3% of patients had a pathological positive/close margin (n = 9 tumor on ink and n = 36 <2 mm). Adjuvant radiation was administered to 11 patients with a positive or close margin. At a median follow-up of 12 years, LR was 3.4% (n = 10). None of the patients with LR had a positive or close margin. Additionally, none of the patients who received radiation developed LR. Risk of recurrence after mastectomy for DCIS is low and appears to be unrelated to margin status or the use of radiation therapy. [Display omitted] •Local recurrence for patients treated with mastectomy for DCIS is low and immediate reconstruction does not increase this risk.•Close or positive surgical margins were seen more frequently in patients undergoing nipple or skin sparing mastectomy with reconstruction.•Risk of local recurrence did not appear to be associated with surgical margin width.

Introduction Resection margin status is the important prognostic factor in resected perihilar cholangiocarcinoma (pCCA). Although the impact of ductal margin (DM) was reported in many studies, the influence of radial margin (RM) is unclear. This study aims to investigate the effect of positive RM on survival. Methods Patients with pCCA underwent curative resection between 2013 and 2018 were retrospectively reviewed. Resection margin status was divided into negative resection margin (R0) and positive resection margin (R1); positive RM alone (RM+) and positive DM with or without positive RM (DM+). Results Of the 167 pCCA patients, 62 (37.1%) had R1 margin. Among 62 R1 patients; 17 (27.4%) had positive DM alone, 20 (32.3%) had positive RM alone and 25 (40.3%) had both positive DM and RM. The R1 patients had a significantly greater number of lymph node metastasis (LNM) and advanced tumor staging than R0 patients, however there was no difference between the RM + and DM + patients. The median survival time of patients with RM + was significantly poorer than R0 patients (13.8 vs. 24.5 months; p  < 0.001, respectively) and similar to the DM + patients (9.1 months, p  = 0.556). However, in patients with LNM, those who underwent R0 resection had no statistically significant difference in survival outcomes compared to those with R1 resection. Conclusion Positive resection margin remains the important prognostic factor, and positive RM is common in these patients. Positive RM also had a comparable effect on survival as positive DM. As a result, in pCCA, surgical resection should target both RM and DM.